{
  "type": "Script",
  "span": {
    "start": 56,
    "end": 1051,
    "ctxt": 0
  },
  "body": [
    {
      "type": "TsInterfaceDeclaration",
      "span": {
        "start": 56,
        "end": 87,
        "ctxt": 0
      },
      "id": {
        "type": "Identifier",
        "span": {
          "start": 66,
          "end": 70,
          "ctxt": 0
        },
        "value": "Base",
        "optional": false
      },
      "declare": false,
      "typeParams": null,
      "extends": [],
      "body": {
        "type": "TsInterfaceBody",
        "span": {
          "start": 71,
          "end": 87,
          "ctxt": 0
        },
        "body": [
          {
            "type": "TsPropertySignature",
            "span": {
              "start": 73,
              "end": 85,
              "ctxt": 0
            },
            "readonly": false,
            "key": {
              "type": "Identifier",
              "span": {
                "start": 73,
                "end": 76,
                "ctxt": 0
              },
              "value": "foo",
              "optional": false
            },
            "computed": false,
            "optional": false,
            "init": null,
            "params": [],
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 76,
                "end": 84,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsKeywordType",
                "span": {
                  "start": 78,
                  "end": 84,
                  "ctxt": 0
                },
                "kind": "string"
              }
            },
            "typeParams": null
          }
        ]
      }
    },
    {
      "type": "TsInterfaceDeclaration",
      "span": {
        "start": 88,
        "end": 135,
        "ctxt": 0
      },
      "id": {
        "type": "Identifier",
        "span": {
          "start": 98,
          "end": 105,
          "ctxt": 0
        },
        "value": "Derived",
        "optional": false
      },
      "declare": false,
      "typeParams": null,
      "extends": [
        {
          "type": "TsExpressionWithTypeArguments",
          "span": {
            "start": 114,
            "end": 118,
            "ctxt": 0
          },
          "expression": {
            "type": "Identifier",
            "span": {
              "start": 114,
              "end": 118,
              "ctxt": 0
            },
            "value": "Base",
            "optional": false
          },
          "typeArguments": null
        }
      ],
      "body": {
        "type": "TsInterfaceBody",
        "span": {
          "start": 119,
          "end": 135,
          "ctxt": 0
        },
        "body": [
          {
            "type": "TsPropertySignature",
            "span": {
              "start": 121,
              "end": 133,
              "ctxt": 0
            },
            "readonly": false,
            "key": {
              "type": "Identifier",
              "span": {
                "start": 121,
                "end": 124,
                "ctxt": 0
              },
              "value": "bar",
              "optional": false
            },
            "computed": false,
            "optional": false,
            "init": null,
            "params": [],
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 124,
                "end": 132,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsKeywordType",
                "span": {
                  "start": 126,
                  "end": 132,
                  "ctxt": 0
                },
                "kind": "string"
              }
            },
            "typeParams": null
          }
        ]
      }
    },
    {
      "type": "TsInterfaceDeclaration",
      "span": {
        "start": 136,
        "end": 187,
        "ctxt": 0
      },
      "id": {
        "type": "Identifier",
        "span": {
          "start": 146,
          "end": 154,
          "ctxt": 0
        },
        "value": "Derived2",
        "optional": false
      },
      "declare": false,
      "typeParams": null,
      "extends": [
        {
          "type": "TsExpressionWithTypeArguments",
          "span": {
            "start": 163,
            "end": 170,
            "ctxt": 0
          },
          "expression": {
            "type": "Identifier",
            "span": {
              "start": 163,
              "end": 170,
              "ctxt": 0
            },
            "value": "Derived",
            "optional": false
          },
          "typeArguments": null
        }
      ],
      "body": {
        "type": "TsInterfaceBody",
        "span": {
          "start": 171,
          "end": 187,
          "ctxt": 0
        },
        "body": [
          {
            "type": "TsPropertySignature",
            "span": {
              "start": 173,
              "end": 185,
              "ctxt": 0
            },
            "readonly": false,
            "key": {
              "type": "Identifier",
              "span": {
                "start": 173,
                "end": 176,
                "ctxt": 0
              },
              "value": "baz",
              "optional": false
            },
            "computed": false,
            "optional": false,
            "init": null,
            "params": [],
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 176,
                "end": 184,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsKeywordType",
                "span": {
                  "start": 178,
                  "end": 184,
                  "ctxt": 0
                },
                "kind": "string"
              }
            },
            "typeParams": null
          }
        ]
      }
    },
    {
      "type": "TsInterfaceDeclaration",
      "span": {
        "start": 189,
        "end": 227,
        "ctxt": 0
      },
      "id": {
        "type": "Identifier",
        "span": {
          "start": 199,
          "end": 200,
          "ctxt": 0
        },
        "value": "A",
        "optional": false
      },
      "declare": false,
      "typeParams": null,
      "extends": [],
      "body": {
        "type": "TsInterfaceBody",
        "span": {
          "start": 201,
          "end": 227,
          "ctxt": 0
        },
        "body": [
          {
            "type": "TsIndexSignature",
            "params": [
              {
                "type": "Identifier",
                "span": {
                  "start": 208,
                  "end": 217,
                  "ctxt": 0
                },
                "value": "x",
                "optional": false,
                "typeAnnotation": {
                  "type": "TsTypeAnnotation",
                  "span": {
                    "start": 209,
                    "end": 217,
                    "ctxt": 0
                  },
                  "typeAnnotation": {
                    "type": "TsKeywordType",
                    "span": {
                      "start": 211,
                      "end": 217,
                      "ctxt": 0
                    },
                    "kind": "string"
                  }
                }
              }
            ],
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 218,
                "end": 224,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsTypeReference",
                "span": {
                  "start": 220,
                  "end": 224,
                  "ctxt": 0
                },
                "typeName": {
                  "type": "Identifier",
                  "span": {
                    "start": 220,
                    "end": 224,
                    "ctxt": 0
                  },
                  "value": "Base",
                  "optional": false
                },
                "typeParams": null
              }
            },
            "readonly": false,
            "static": false,
            "span": {
              "start": 207,
              "end": 225,
              "ctxt": 0
            }
          }
        ]
      }
    },
    {
      "type": "VariableDeclaration",
      "span": {
        "start": 229,
        "end": 238,
        "ctxt": 0
      },
      "kind": "var",
      "declare": false,
      "declarations": [
        {
          "type": "VariableDeclarator",
          "span": {
            "start": 233,
            "end": 237,
            "ctxt": 0
          },
          "id": {
            "type": "Identifier",
            "span": {
              "start": 233,
              "end": 234,
              "ctxt": 0
            },
            "value": "a",
            "optional": false,
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 234,
                "end": 237,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsTypeReference",
                "span": {
                  "start": 236,
                  "end": 237,
                  "ctxt": 0
                },
                "typeName": {
                  "type": "Identifier",
                  "span": {
                    "start": 236,
                    "end": 237,
                    "ctxt": 0
                  },
                  "value": "A",
                  "optional": false
                },
                "typeParams": null
              }
            }
          },
          "init": null,
          "definite": false
        }
      ]
    },
    {
      "type": "VariableDeclaration",
      "span": {
        "start": 240,
        "end": 272,
        "ctxt": 0
      },
      "kind": "var",
      "declare": false,
      "declarations": [
        {
          "type": "VariableDeclarator",
          "span": {
            "start": 244,
            "end": 272,
            "ctxt": 0
          },
          "id": {
            "type": "Identifier",
            "span": {
              "start": 244,
              "end": 245,
              "ctxt": 0
            },
            "value": "b",
            "optional": false,
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 245,
                "end": 272,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsTypeLiteral",
                "span": {
                  "start": 247,
                  "end": 272,
                  "ctxt": 0
                },
                "members": [
                  {
                    "type": "TsIndexSignature",
                    "params": [
                      {
                        "type": "Identifier",
                        "span": {
                          "start": 250,
                          "end": 259,
                          "ctxt": 0
                        },
                        "value": "x",
                        "optional": false,
                        "typeAnnotation": {
                          "type": "TsTypeAnnotation",
                          "span": {
                            "start": 251,
                            "end": 259,
                            "ctxt": 0
                          },
                          "typeAnnotation": {
                            "type": "TsKeywordType",
                            "span": {
                              "start": 253,
                              "end": 259,
                              "ctxt": 0
                            },
                            "kind": "string"
                          }
                        }
                      }
                    ],
                    "typeAnnotation": {
                      "type": "TsTypeAnnotation",
                      "span": {
                        "start": 260,
                        "end": 269,
                        "ctxt": 0
                      },
                      "typeAnnotation": {
                        "type": "TsTypeReference",
                        "span": {
                          "start": 262,
                          "end": 269,
                          "ctxt": 0
                        },
                        "typeName": {
                          "type": "Identifier",
                          "span": {
                            "start": 262,
                            "end": 269,
                            "ctxt": 0
                          },
                          "value": "Derived",
                          "optional": false
                        },
                        "typeParams": null
                      }
                    },
                    "readonly": false,
                    "static": false,
                    "span": {
                      "start": 249,
                      "end": 270,
                      "ctxt": 0
                    }
                  }
                ]
              }
            }
          },
          "init": null,
          "definite": false
        }
      ]
    },
    {
      "type": "ExpressionStatement",
      "span": {
        "start": 273,
        "end": 279,
        "ctxt": 0
      },
      "expression": {
        "type": "AssignmentExpression",
        "span": {
          "start": 273,
          "end": 278,
          "ctxt": 0
        },
        "operator": "=",
        "left": {
          "type": "Identifier",
          "span": {
            "start": 273,
            "end": 274,
            "ctxt": 0
          },
          "value": "a",
          "optional": false,
          "typeAnnotation": null
        },
        "right": {
          "type": "Identifier",
          "span": {
            "start": 277,
            "end": 278,
            "ctxt": 0
          },
          "value": "b",
          "optional": false
        }
      }
    },
    {
      "type": "ExpressionStatement",
      "span": {
        "start": 286,
        "end": 292,
        "ctxt": 0
      },
      "expression": {
        "type": "AssignmentExpression",
        "span": {
          "start": 286,
          "end": 291,
          "ctxt": 0
        },
        "operator": "=",
        "left": {
          "type": "Identifier",
          "span": {
            "start": 286,
            "end": 287,
            "ctxt": 0
          },
          "value": "b",
          "optional": false,
          "typeAnnotation": null
        },
        "right": {
          "type": "Identifier",
          "span": {
            "start": 290,
            "end": 291,
            "ctxt": 0
          },
          "value": "a",
          "optional": false
        }
      }
    },
    {
      "type": "VariableDeclaration",
      "span": {
        "start": 303,
        "end": 337,
        "ctxt": 0
      },
      "kind": "var",
      "declare": false,
      "declarations": [
        {
          "type": "VariableDeclarator",
          "span": {
            "start": 307,
            "end": 337,
            "ctxt": 0
          },
          "id": {
            "type": "Identifier",
            "span": {
              "start": 307,
              "end": 309,
              "ctxt": 0
            },
            "value": "b2",
            "optional": false,
            "typeAnnotation": {
              "type": "TsTypeAnnotation",
              "span": {
                "start": 309,
                "end": 337,
                "ctxt": 0
              },
              "typeAnnotation": {
                "type": "TsTypeLiteral",
                "span": {
                  "start": 311,
                  "end": 337,
                  "ctxt": 0
                },
                "members": [
                  {
                    "type": "TsIndexSignature",
                    "params": [
                      {
                        "type": "Identifier",
                        "span": {
                          "start": 314,
                          "end": 323,
                          "ctxt": 0
                        },
                        "value": "x",
                        "optional": false,
                        "typeAnnotation": {
                          "type": "TsTypeAnnotation",
                          "span": {
                            "start": 315,
                            "end": 323,
                            "ctxt": 0
                          },
                          "typeAnnotation": {
                            "type": "TsKeywordType",
                            "span": {
                              "start": 317,
                              "end": 323,
                              "ctxt": 0
                            },
                            "kind": "string"
                          }
                        }
                      }
                    ],
                    "typeAnnotation": {
                      "type": "TsTypeAnnotation",
                      "span": {
                        "start": 324,
                        "end": 334,
                        "ctxt": 0
                      },
                      "typeAnnotation": {
                        "type": "TsTypeReference",
                        "span": {
                          "start": 326,
                          "end": 334,
                          "ctxt": 0
                        },
                        "typeName": {
                          "type": "Identifier",
                          "span": {
                            "start": 326,
                            "end": 334,
                            "ctxt": 0
                          },
                          "value": "Derived2",
                          "optional": false
                        },
                        "typeParams": null
                      }
                    },
                    "readonly": false,
                    "static": false,
                    "span": {
                      "start": 313,
                      "end": 335,
                      "ctxt": 0
                    }
                  }
                ]
              }
            }
          },
          "init": null,
          "definite": false
        }
      ]
    },
    {
      "type": "ExpressionStatement",
      "span": {
        "start": 338,
        "end": 345,
        "ctxt": 0
      },
      "expression": {
        "type": "AssignmentExpression",
        "span": {
          "start": 338,
          "end": 344,
          "ctxt": 0
        },
        "operator": "=",
        "left": {
          "type": "Identifier",
          "span": {
            "start": 338,
            "end": 339,
            "ctxt": 0
          },
          "value": "a",
          "optional": false,
          "typeAnnotation": null
        },
        "right": {
          "type": "Identifier",
          "span": {
            "start": 342,
            "end": 344,
            "ctxt": 0
          },
          "value": "b2",
          "optional": false
        }
      }
    },
    {
      "type": "ExpressionStatement",
      "span": {
        "start": 352,
        "end": 359,
        "ctxt": 0
      },
      "expression": {
        "type": "AssignmentExpression",
        "span": {
          "start": 352,
          "end": 358,
          "ctxt": 0
        },
        "operator": "=",
        "left": {
          "type": "Identifier",
          "span": {
            "start": 352,
            "end": 354,
            "ctxt": 0
          },
          "value": "b2",
          "optional": false,
          "typeAnnotation": null
        },
        "right": {
          "type": "Identifier",
          "span": {
            "start": 357,
            "end": 358,
            "ctxt": 0
          },
          "value": "a",
          "optional": false
        }
      }
    },
    {
      "type": "TsModuleDeclaration",
      "span": {
        "start": 370,
        "end": 1051,
        "ctxt": 0
      },
      "declare": false,
      "global": false,
      "id": {
        "type": "Identifier",
        "span": {
          "start": 377,
          "end": 385,
          "ctxt": 0
        },
        "value": "Generics",
        "optional": false
      },
      "body": {
        "type": "TsModuleBlock",
        "span": {
          "start": 386,
          "end": 1051,
          "ctxt": 0
        },
        "body": [
          {
            "type": "TsInterfaceDeclaration",
            "span": {
              "start": 392,
              "end": 451,
              "ctxt": 0
            },
            "id": {
              "type": "Identifier",
              "span": {
                "start": 402,
                "end": 403,
                "ctxt": 0
              },
              "value": "A",
              "optional": false
            },
            "declare": false,
            "typeParams": {
              "type": "TsTypeParameterDeclaration",
              "span": {
                "start": 403,
                "end": 419,
                "ctxt": 0
              },
              "parameters": [
                {
                  "type": "TsTypeParameter",
                  "span": {
                    "start": 404,
                    "end": 418,
                    "ctxt": 0
                  },
                  "name": {
                    "type": "Identifier",
                    "span": {
                      "start": 404,
                      "end": 405,
                      "ctxt": 0
                    },
                    "value": "T",
                    "optional": false
                  },
                  "in": false,
                  "out": false,
                  "const": false,
                  "constraint": {
                    "type": "TsTypeReference",
                    "span": {
                      "start": 414,
                      "end": 418,
                      "ctxt": 0
                    },
                    "typeName": {
                      "type": "Identifier",
                      "span": {
                        "start": 414,
                        "end": 418,
                        "ctxt": 0
                      },
                      "value": "Base",
                      "optional": false
                    },
                    "typeParams": null
                  },
                  "default": null
                }
              ]
            },
            "extends": [],
            "body": {
              "type": "TsInterfaceBody",
              "span": {
                "start": 420,
                "end": 451,
                "ctxt": 0
              },
              "body": [
                {
                  "type": "TsIndexSignature",
                  "params": [
                    {
                      "type": "Identifier",
                      "span": {
                        "start": 431,
                        "end": 440,
                        "ctxt": 0
                      },
                      "value": "x",
                      "optional": false,
                      "typeAnnotation": {
                        "type": "TsTypeAnnotation",
                        "span": {
                          "start": 432,
                          "end": 440,
                          "ctxt": 0
                        },
                        "typeAnnotation": {
                          "type": "TsKeywordType",
                          "span": {
                            "start": 434,
                            "end": 440,
                            "ctxt": 0
                          },
                          "kind": "string"
                        }
                      }
                    }
                  ],
                  "typeAnnotation": {
                    "type": "TsTypeAnnotation",
                    "span": {
                      "start": 441,
                      "end": 444,
                      "ctxt": 0
                    },
                    "typeAnnotation": {
                      "type": "TsTypeReference",
                      "span": {
                        "start": 443,
                        "end": 444,
                        "ctxt": 0
                      },
                      "typeName": {
                        "type": "Identifier",
                        "span": {
                          "start": 443,
                          "end": 444,
                          "ctxt": 0
                        },
                        "value": "T",
                        "optional": false
                      },
                      "typeParams": null
                    }
                  },
                  "readonly": false,
                  "static": false,
                  "span": {
                    "start": 430,
                    "end": 445,
                    "ctxt": 0
                  }
                }
              ]
            }
          },
          {
            "type": "TsInterfaceDeclaration",
            "span": {
              "start": 457,
              "end": 528,
              "ctxt": 0
            },
            "id": {
              "type": "Identifier",
              "span": {
                "start": 467,
                "end": 468,
                "ctxt": 0
              },
              "value": "B",
              "optional": false
            },
            "declare": false,
            "typeParams": null,
            "extends": [
              {
                "type": "TsExpressionWithTypeArguments",
                "span": {
                  "start": 477,
                  "end": 484,
                  "ctxt": 0
                },
                "expression": {
                  "type": "Identifier",
                  "span": {
                    "start": 477,
                    "end": 478,
                    "ctxt": 0
                  },
                  "value": "A",
                  "optional": false
                },
                "typeArguments": {
                  "type": "TsTypeParameterInstantiation",
                  "span": {
                    "start": 478,
                    "end": 484,
                    "ctxt": 0
                  },
                  "params": [
                    {
                      "type": "TsTypeReference",
                      "span": {
                        "start": 479,
                        "end": 483,
                        "ctxt": 0
                      },
                      "typeName": {
                        "type": "Identifier",
                        "span": {
                          "start": 479,
                          "end": 483,
                          "ctxt": 0
                        },
                        "value": "Base",
                        "optional": false
                      },
                      "typeParams": null
                    }
                  ]
                }
              }
            ],
            "body": {
              "type": "TsInterfaceBody",
              "span": {
                "start": 485,
                "end": 528,
                "ctxt": 0
              },
              "body": [
                {
                  "type": "TsIndexSignature",
                  "params": [
                    {
                      "type": "Identifier",
                      "span": {
                        "start": 496,
                        "end": 505,
                        "ctxt": 0
                      },
                      "value": "x",
                      "optional": false,
                      "typeAnnotation": {
                        "type": "TsTypeAnnotation",
                        "span": {
                          "start": 497,
                          "end": 505,
                          "ctxt": 0
                        },
                        "typeAnnotation": {
                          "type": "TsKeywordType",
                          "span": {
                            "start": 499,
                            "end": 505,
                            "ctxt": 0
                          },
                          "kind": "string"
                        }
                      }
                    }
                  ],
                  "typeAnnotation": {
                    "type": "TsTypeAnnotation",
                    "span": {
                      "start": 506,
                      "end": 515,
                      "ctxt": 0
                    },
                    "typeAnnotation": {
                      "type": "TsTypeReference",
                      "span": {
                        "start": 508,
                        "end": 515,
                        "ctxt": 0
                      },
                      "typeName": {
                        "type": "Identifier",
                        "span": {
                          "start": 508,
                          "end": 515,
                          "ctxt": 0
                        },
                        "value": "Derived",
                        "optional": false
                      },
                      "typeParams": null
                    }
                  },
                  "readonly": false,
                  "static": false,
                  "span": {
                    "start": 495,
                    "end": 516,
                    "ctxt": 0
                  }
                }
              ]
            }
          },
          {
            "type": "VariableDeclaration",
            "span": {
              "start": 534,
              "end": 568,
              "ctxt": 0
            },
            "kind": "var",
            "declare": false,
            "declarations": [
              {
                "type": "VariableDeclarator",
                "span": {
                  "start": 538,
                  "end": 567,
                  "ctxt": 0
                },
                "id": {
                  "type": "Identifier",
                  "span": {
                    "start": 538,
                    "end": 540,
                    "ctxt": 0
                  },
                  "value": "b1",
                  "optional": false,
                  "typeAnnotation": {
                    "type": "TsTypeAnnotation",
                    "span": {
                      "start": 540,
                      "end": 567,
                      "ctxt": 0
                    },
                    "typeAnnotation": {
                      "type": "TsTypeLiteral",
                      "span": {
                        "start": 542,
                        "end": 567,
                        "ctxt": 0
                      },
                      "members": [
                        {
                          "type": "TsIndexSignature",
                          "params": [
                            {
                              "type": "Identifier",
                              "span": {
                                "start": 545,
                                "end": 554,
                                "ctxt": 0
                              },
                              "value": "x",
                              "optional": false,
                              "typeAnnotation": {
                                "type": "TsTypeAnnotation",
                                "span": {
                                  "start": 546,
                                  "end": 554,
                                  "ctxt": 0
                                },
                                "typeAnnotation": {
                                  "type": "TsKeywordType",
                                  "span": {
                                    "start": 548,
                                    "end": 554,
                                    "ctxt": 0
                                  },
                                  "kind": "string"
                                }
                              }
                            }
                          ],
                          "typeAnnotation": {
                            "type": "TsTypeAnnotation",
                            "span": {
                              "start": 555,
                              "end": 564,
                              "ctxt": 0
                            },
                            "typeAnnotation": {
                              "type": "TsTypeReference",
                              "span": {
                                "start": 557,
                                "end": 564,
                                "ctxt": 0
                              },
                              "typeName": {
                                "type": "Identifier",
                                "span": {
                                  "start": 557,
                                  "end": 564,
                                  "ctxt": 0
                                },
                                "value": "Derived",
                                "optional": false
                              },
                              "typeParams": null
                            }
                          },
                          "readonly": false,
                          "static": false,
                          "span": {
                            "start": 544,
                            "end": 565,
                            "ctxt": 0
                          }
                        }
                      ]
                    }
                  }
                },
                "init": null,
                "definite": false
              }
            ]
          },
          {
            "type": "VariableDeclaration",
            "span": {
              "start": 573,
              "end": 589,
              "ctxt": 0
            },
            "kind": "var",
            "declare": false,
            "declarations": [
              {
                "type": "VariableDeclarator",
                "span": {
                  "start": 577,
                  "end": 588,
                  "ctxt": 0
                },
                "id": {
                  "type": "Identifier",
                  "span": {
                    "start": 577,
                    "end": 579,
                    "ctxt": 0
                  },
                  "value": "a1",
                  "optional": false,
                  "typeAnnotation": {
                    "type": "TsTypeAnnotation",
                    "span": {
                      "start": 579,
                      "end": 588,
                      "ctxt": 0
                    },
                    "typeAnnotation": {
                      "type": "TsTypeReference",
                      "span": {
                        "start": 581,
                        "end": 588,
                        "ctxt": 0
                      },
                      "typeName": {
                        "type": "Identifier",
                        "span": {
                          "start": 581,
                          "end": 582,
                          "ctxt": 0
                        },
                        "value": "A",
                        "optional": false
                      },
                      "typeParams": {
                        "type": "TsTypeParameterInstantiation",
                        "span": {
                          "start": 582,
                          "end": 588,
                          "ctxt": 0
                        },
                        "params": [
                          {
                            "type": "TsTypeReference",
                            "span": {
                              "start": 583,
                              "end": 587,
                              "ctxt": 0
                            },
                            "typeName": {
                              "type": "Identifier",
                              "span": {
                                "start": 583,
                                "end": 587,
                                "ctxt": 0
                              },
                              "value": "Base",
                              "optional": false
                            },
                            "typeParams": null
                          }
                        ]
                      }
                    }
                  }
                },
                "init": null,
                "definite": false
              }
            ]
          },
          {
            "type": "ExpressionStatement",
            "span": {
              "start": 594,
              "end": 602,
              "ctxt": 0
            },
            "expression": {
              "type": "AssignmentExpression",
              "span": {
                "start": 594,
                "end": 601,
                "ctxt": 0
              },
              "operator": "=",
              "left": {
                "type": "Identifier",
                "span": {
                  "start": 594,
                  "end": 596,
                  "ctxt": 0
                },
                "value": "a1",
                "optional": false,
                "typeAnnotation": null
              },
              "right": {
                "type": "Identifier",
                "span": {
                  "start": 599,
                  "end": 601,
                  "ctxt": 0
                },
                "value": "b1",
                "optional": false
              }
            }
          },
          {
            "type": "ExpressionStatement",
            "span": {
              "start": 613,
              "end": 621,
              "ctxt": 0
            },
            "expression": {
              "type": "AssignmentExpression",
              "span": {
                "start": 613,
                "end": 620,
                "ctxt": 0
              },
              "operator": "=",
              "left": {
                "type": "Identifier",
                "span": {
                  "start": 613,
                  "end": 615,
                  "ctxt": 0
                },
                "value": "b1",
                "optional": false,
                "typeAnnotation": null
              },
              "right": {
                "type": "Identifier",
                "span": {
                  "start": 618,
                  "end": 620,
                  "ctxt": 0
                },
                "value": "a1",
                "optional": false
              }
            }
          },
          {
            "type": "TsInterfaceDeclaration",
            "span": {
              "start": 636,
              "end": 709,
              "ctxt": 0
            },
            "id": {
              "type": "Identifier",
              "span": {
                "start": 646,
                "end": 648,
                "ctxt": 0
              },
              "value": "B2",
              "optional": false
            },
            "declare": false,
            "typeParams": null,
            "extends": [
              {
                "type": "TsExpressionWithTypeArguments",
                "span": {
                  "start": 657,
                  "end": 664,
                  "ctxt": 0
                },
                "expression": {
                  "type": "Identifier",
                  "span": {
                    "start": 657,
                    "end": 658,
                    "ctxt": 0
                  },
                  "value": "A",
                  "optional": false
                },
                "typeArguments": {
                  "type": "TsTypeParameterInstantiation",
                  "span": {
                    "start": 658,
                    "end": 664,
                    "ctxt": 0
                  },
                  "params": [
                    {
                      "type": "TsTypeReference",
                      "span": {
                        "start": 659,
                        "end": 663,
                        "ctxt": 0
                      },
                      "typeName": {
                        "type": "Identifier",
                        "span": {
                          "start": 659,
                          "end": 663,
                          "ctxt": 0
                        },
                        "value": "Base",
                        "optional": false
                      },
                      "typeParams": null
                    }
                  ]
                }
              }
            ],
            "body": {
              "type": "TsInterfaceBody",
              "span": {
                "start": 665,
                "end": 709,
                "ctxt": 0
              },
              "body": [
                {
                  "type": "TsIndexSignature",
                  "params": [
                    {
                      "type": "Identifier",
                      "span": {
                        "start": 676,
                        "end": 685,
                        "ctxt": 0
                      },
                      "value": "x",
                      "optional": false,
                      "typeAnnotation": {
                        "type": "TsTypeAnnotation",
                        "span": {
                          "start": 677,
                          "end": 685,
                          "ctxt": 0
                        },
                        "typeAnnotation": {
                          "type": "TsKeywordType",
                          "span": {
                            "start": 679,
                            "end": 685,
                            "ctxt": 0
                          },
                          "kind": "string"
                        }
                      }
                    }
                  ],
                  "typeAnnotation": {
                    "type": "TsTypeAnnotation",
                    "span": {
                      "start": 686,
                      "end": 696,
                      "ctxt": 0
                    },
                    "typeAnnotation": {
                      "type": "TsTypeReference",
                      "span": {
                        "start": 688,
                        "end": 696,
                        "ctxt": 0
                      },
                      "typeName": {
                        "type": "Identifier",
                        "span": {
                          "start": 688,
                          "end": 696,
                          "ctxt": 0
                        },
                        "value": "Derived2",
                        "optional": false
                      },
                      "typeParams": null
                    }
                  },
                  "readonly": false,
                  "static": false,
                  "span": {
                    "start": 675,
                    "end": 697,
                    "ctxt": 0
                  }
                }
              ]
            }
          },
          {
            "type": "VariableDeclaration",
            "span": {
              "start": 715,
              "end": 750,
              "ctxt": 0
            },
            "kind": "var",
            "declare": false,
            "declarations": [
              {
                "type": "VariableDeclarator",
                "span": {
                  "start": 719,
                  "end": 749,
                  "ctxt": 0
                },
                "id": {
                  "type": "Identifier",
                  "span": {
                    "start": 719,
                    "end": 721,
                    "ctxt": 0
                  },
                  "value": "b2",
                  "optional": false,
                  "typeAnnotation": {
                    "type": "TsTypeAnnotation",
                    "span": {
                      "start": 721,
                      "end": 749,
                      "ctxt": 0
                    },
                    "typeAnnotation": {
                      "type": "TsTypeLiteral",
                      "span": {
                        "start": 723,
                        "end": 749,
                        "ctxt": 0
                      },
                      "members": [
                        {
                          "type": "TsIndexSignature",
                          "params": [
                            {
                              "type": "Identifier",
                              "span": {
                                "start": 726,
                                "end": 735,
                                "ctxt": 0
                              },
                              "value": "x",
                              "optional": false,
                              "typeAnnotation": {
                                "type": "TsTypeAnnotation",
                                "span": {
                                  "start": 727,
                                  "end": 735,
                                  "ctxt": 0
                                },
                                "typeAnnotation": {
                                  "type": "TsKeywordType",
                                  "span": {
                                    "start": 729,
                                    "end": 735,
                                    "ctxt": 0
                                  },
                                  "kind": "string"
                                }
                              }
                            }
                          ],
                          "typeAnnotation": {
                            "type": "TsTypeAnnotation",
                            "span": {
                              "start": 736,
                              "end": 746,
                              "ctxt": 0
                            },
                            "typeAnnotation": {
                              "type": "TsTypeReference",
                              "span": {
                                "start": 738,
                                "end": 746,
                                "ctxt": 0
                              },
                              "typeName": {
                                "type": "Identifier",
                                "span": {
                                  "start": 738,
                                  "end": 746,
                                  "ctxt": 0
                                },
                                "value": "Derived2",
                                "optional": false
                              },
                              "typeParams": null
                            }
                          },
                          "readonly": false,
                          "static": false,
                          "span": {
                            "start": 725,
                            "end": 747,
                            "ctxt": 0
                          }
                        }
                      ]
                    }
                  }
                },
                "init": null,
                "definite": false
              }
            ]
          },
          {
            "type": "ExpressionStatement",
            "span": {
              "start": 755,
              "end": 763,
              "ctxt": 0
            },
            "expression": {
              "type": "AssignmentExpression",
              "span": {
                "start": 755,
                "end": 762,
                "ctxt": 0
              },
              "operator": "=",
              "left": {
                "type": "Identifier",
                "span": {
                  "start": 755,
                  "end": 757,
                  "ctxt": 0
                },
                "value": "a1",
                "optional": false,
                "typeAnnotation": null
              },
              "right": {
                "type": "Identifier",
                "span": {
                  "start": 760,
                  "end": 762,
                  "ctxt": 0
                },
                "value": "b2",
                "optional": false
              }
            }
          },
          {
            "type": "ExpressionStatement",
            "span": {
              "start": 774,
              "end": 782,
              "ctxt": 0
            },
            "expression": {
              "type": "AssignmentExpression",
              "span": {
                "start": 774,
                "end": 781,
                "ctxt": 0
              },
              "operator": "=",
              "left": {
                "type": "Identifier",
                "span": {
                  "start": 774,
                  "end": 776,
                  "ctxt": 0
                },
                "value": "b2",
                "optional": false,
                "typeAnnotation": null
              },
              "right": {
                "type": "Identifier",
                "span": {
                  "start": 779,
                  "end": 781,
                  "ctxt": 0
                },
                "value": "a1",
                "optional": false
              }
            }
          },
          {
            "type": "FunctionDeclaration",
            "identifier": {
              "type": "Identifier",
              "span": {
                "start": 806,
                "end": 809,
                "ctxt": 0
              },
              "value": "foo",
              "optional": false
            },
            "declare": false,
            "params": [],
            "decorators": [],
            "span": {
              "start": 797,
              "end": 1049,
              "ctxt": 0
            },
            "body": {
              "type": "BlockStatement",
              "span": {
                "start": 828,
                "end": 1049,
                "ctxt": 0
              },
              "stmts": [
                {
                  "type": "VariableDeclaration",
                  "span": {
                    "start": 838,
                    "end": 872,
                    "ctxt": 0
                  },
                  "kind": "var",
                  "declare": false,
                  "declarations": [
                    {
                      "type": "VariableDeclarator",
                      "span": {
                        "start": 842,
                        "end": 871,
                        "ctxt": 0
                      },
                      "id": {
                        "type": "Identifier",
                        "span": {
                          "start": 842,
                          "end": 844,
                          "ctxt": 0
                        },
                        "value": "b3",
                        "optional": false,
                        "typeAnnotation": {
                          "type": "TsTypeAnnotation",
                          "span": {
                            "start": 844,
                            "end": 871,
                            "ctxt": 0
                          },
                          "typeAnnotation": {
                            "type": "TsTypeLiteral",
                            "span": {
                              "start": 846,
                              "end": 871,
                              "ctxt": 0
                            },
                            "members": [
                              {
                                "type": "TsIndexSignature",
                                "params": [
                                  {
                                    "type": "Identifier",
                                    "span": {
                                      "start": 849,
                                      "end": 858,
                                      "ctxt": 0
                                    },
                                    "value": "x",
                                    "optional": false,
                                    "typeAnnotation": {
                                      "type": "TsTypeAnnotation",
                                      "span": {
                                        "start": 850,
                                        "end": 858,
                                        "ctxt": 0
                                      },
                                      "typeAnnotation": {
                                        "type": "TsKeywordType",
                                        "span": {
                                          "start": 852,
                                          "end": 858,
                                          "ctxt": 0
                                        },
                                        "kind": "string"
                                      }
                                    }
                                  }
                                ],
                                "typeAnnotation": {
                                  "type": "TsTypeAnnotation",
                                  "span": {
                                    "start": 859,
                                    "end": 868,
                                    "ctxt": 0
                                  },
                                  "typeAnnotation": {
                                    "type": "TsTypeReference",
                                    "span": {
                                      "start": 861,
                                      "end": 868,
                                      "ctxt": 0
                                    },
                                    "typeName": {
                                      "type": "Identifier",
                                      "span": {
                                        "start": 861,
                                        "end": 868,
                                        "ctxt": 0
                                      },
                                      "value": "Derived",
                                      "optional": false
                                    },
                                    "typeParams": null
                                  }
                                },
                                "readonly": false,
                                "static": false,
                                "span": {
                                  "start": 848,
                                  "end": 869,
                                  "ctxt": 0
                                }
                              }
                            ]
                          }
                        }
                      },
                      "init": null,
                      "definite": false
                    }
                  ]
                },
                {
                  "type": "VariableDeclaration",
                  "span": {
                    "start": 881,
                    "end": 894,
                    "ctxt": 0
                  },
                  "kind": "var",
                  "declare": false,
                  "declarations": [
                    {
                      "type": "VariableDeclarator",
                      "span": {
                        "start": 885,
                        "end": 893,
                        "ctxt": 0
                      },
                      "id": {
                        "type": "Identifier",
                        "span": {
                          "start": 885,
                          "end": 887,
                          "ctxt": 0
                        },
                        "value": "a3",
                        "optional": false,
                        "typeAnnotation": {
                          "type": "TsTypeAnnotation",
                          "span": {
                            "start": 887,
                            "end": 893,
                            "ctxt": 0
                          },
                          "typeAnnotation": {
                            "type": "TsTypeReference",
                            "span": {
                              "start": 889,
                              "end": 893,
                              "ctxt": 0
                            },
                            "typeName": {
                              "type": "Identifier",
                              "span": {
                                "start": 889,
                                "end": 890,
                                "ctxt": 0
                              },
                              "value": "A",
                              "optional": false
                            },
                            "typeParams": {
                              "type": "TsTypeParameterInstantiation",
                              "span": {
                                "start": 890,
                                "end": 893,
                                "ctxt": 0
                              },
                              "params": [
                                {
                                  "type": "TsTypeReference",
                                  "span": {
                                    "start": 891,
                                    "end": 892,
                                    "ctxt": 0
                                  },
                                  "typeName": {
                                    "type": "Identifier",
                                    "span": {
                                      "start": 891,
                                      "end": 892,
                                      "ctxt": 0
                                    },
                                    "value": "T",
                                    "optional": false
                                  },
                                  "typeParams": null
                                }
                              ]
                            }
                          }
                        }
                      },
                      "init": null,
                      "definite": false
                    }
                  ]
                },
                {
                  "type": "ExpressionStatement",
                  "span": {
                    "start": 903,
                    "end": 911,
                    "ctxt": 0
                  },
                  "expression": {
                    "type": "AssignmentExpression",
                    "span": {
                      "start": 903,
                      "end": 910,
                      "ctxt": 0
                    },
                    "operator": "=",
                    "left": {
                      "type": "Identifier",
                      "span": {
                        "start": 903,
                        "end": 905,
                        "ctxt": 0
                      },
                      "value": "a3",
                      "optional": false,
                      "typeAnnotation": null
                    },
                    "right": {
                      "type": "Identifier",
                      "span": {
                        "start": 908,
                        "end": 910,
                        "ctxt": 0
                      },
                      "value": "b3",
                      "optional": false
                    }
                  }
                },
                {
                  "type": "ExpressionStatement",
                  "span": {
                    "start": 929,
                    "end": 937,
                    "ctxt": 0
                  },
                  "expression": {
                    "type": "AssignmentExpression",
                    "span": {
                      "start": 929,
                      "end": 936,
                      "ctxt": 0
                    },
                    "operator": "=",
                    "left": {
                      "type": "Identifier",
                      "span": {
                        "start": 929,
                        "end": 931,
                        "ctxt": 0
                      },
                      "value": "b3",
                      "optional": false,
                      "typeAnnotation": null
                    },
                    "right": {
                      "type": "Identifier",
                      "span": {
                        "start": 934,
                        "end": 936,
                        "ctxt": 0
                      },
                      "value": "a3",
                      "optional": false
                    }
                  }
                },
                {
                  "type": "VariableDeclaration",
                  "span": {
                    "start": 956,
                    "end": 991,
                    "ctxt": 0
                  },
                  "kind": "var",
                  "declare": false,
                  "declarations": [
                    {
                      "type": "VariableDeclarator",
                      "span": {
                        "start": 960,
                        "end": 990,
                        "ctxt": 0
                      },
                      "id": {
                        "type": "Identifier",
                        "span": {
                          "start": 960,
                          "end": 962,
                          "ctxt": 0
                        },
                        "value": "b4",
                        "optional": false,
                        "typeAnnotation": {
                          "type": "TsTypeAnnotation",
                          "span": {
                            "start": 962,
                            "end": 990,
                            "ctxt": 0
                          },
                          "typeAnnotation": {
                            "type": "TsTypeLiteral",
                            "span": {
                              "start": 964,
                              "end": 990,
                              "ctxt": 0
                            },
                            "members": [
                              {
                                "type": "TsIndexSignature",
                                "params": [
                                  {
                                    "type": "Identifier",
                                    "span": {
                                      "start": 967,
                                      "end": 976,
                                      "ctxt": 0
                                    },
                                    "value": "x",
                                    "optional": false,
                                    "typeAnnotation": {
                                      "type": "TsTypeAnnotation",
                                      "span": {
                                        "start": 968,
                                        "end": 976,
                                        "ctxt": 0
                                      },
                                      "typeAnnotation": {
                                        "type": "TsKeywordType",
                                        "span": {
                                          "start": 970,
                                          "end": 976,
                                          "ctxt": 0
                                        },
                                        "kind": "string"
                                      }
                                    }
                                  }
                                ],
                                "typeAnnotation": {
                                  "type": "TsTypeAnnotation",
                                  "span": {
                                    "start": 977,
                                    "end": 987,
                                    "ctxt": 0
                                  },
                                  "typeAnnotation": {
                                    "type": "TsTypeReference",
                                    "span": {
                                      "start": 979,
                                      "end": 987,
                                      "ctxt": 0
                                    },
                                    "typeName": {
                                      "type": "Identifier",
                                      "span": {
                                        "start": 979,
                                        "end": 987,
                                        "ctxt": 0
                                      },
                                      "value": "Derived2",
                                      "optional": false
                                    },
                                    "typeParams": null
                                  }
                                },
                                "readonly": false,
                                "static": false,
                                "span": {
                                  "start": 966,
                                  "end": 988,
                                  "ctxt": 0
                                }
                              }
                            ]
                          }
                        }
                      },
                      "init": null,
                      "definite": false
                    }
                  ]
                },
                {
                  "type": "ExpressionStatement",
                  "span": {
                    "start": 1000,
                    "end": 1008,
                    "ctxt": 0
                  },
                  "expression": {
                    "type": "AssignmentExpression",
                    "span": {
                      "start": 1000,
                      "end": 1007,
                      "ctxt": 0
                    },
                    "operator": "=",
                    "left": {
                      "type": "Identifier",
                      "span": {
                        "start": 1000,
                        "end": 1002,
                        "ctxt": 0
                      },
                      "value": "a3",
                      "optional": false,
                      "typeAnnotation": null
                    },
                    "right": {
                      "type": "Identifier",
                      "span": {
                        "start": 1005,
                        "end": 1007,
                        "ctxt": 0
                      },
                      "value": "b4",
                      "optional": false
                    }
                  }
                },
                {
                  "type": "ExpressionStatement",
                  "span": {
                    "start": 1026,
                    "end": 1034,
                    "ctxt": 0
                  },
                  "expression": {
                    "type": "AssignmentExpression",
                    "span": {
                      "start": 1026,
                      "end": 1033,
                      "ctxt": 0
                    },
                    "operator": "=",
                    "left": {
                      "type": "Identifier",
                      "span": {
                        "start": 1026,
                        "end": 1028,
                        "ctxt": 0
                      },
                      "value": "b4",
                      "optional": false,
                      "typeAnnotation": null
                    },
                    "right": {
                      "type": "Identifier",
                      "span": {
                        "start": 1031,
                        "end": 1033,
                        "ctxt": 0
                      },
                      "value": "a3",
                      "optional": false
                    }
                  }
                }
              ]
            },
            "generator": false,
            "async": false,
            "typeParameters": {
              "type": "TsTypeParameterDeclaration",
              "span": {
                "start": 809,
                "end": 825,
                "ctxt": 0
              },
              "parameters": [
                {
                  "type": "TsTypeParameter",
                  "span": {
                    "start": 810,
                    "end": 824,
                    "ctxt": 0
                  },
                  "name": {
                    "type": "Identifier",
                    "span": {
                      "start": 810,
                      "end": 811,
                      "ctxt": 0
                    },
                    "value": "T",
                    "optional": false
                  },
                  "in": false,
                  "out": false,
                  "const": false,
                  "constraint": {
                    "type": "TsTypeReference",
                    "span": {
                      "start": 820,
                      "end": 824,
                      "ctxt": 0
                    },
                    "typeName": {
                      "type": "Identifier",
                      "span": {
                        "start": 820,
                        "end": 824,
                        "ctxt": 0
                      },
                      "value": "Base",
                      "optional": false
                    },
                    "typeParams": null
                  },
                  "default": null
                }
              ]
            },
            "returnType": null
          }
        ]
      }
    }
  ],
  "interpreter": null
}