(Program (ExpressionStatements (Class (Identifier) {+(Method (Identifier) (Params (Other "required_parameter" (Identifier))) (Return (Identifier)))+} {+(Method (Identifier) (Params (Other "required_parameter" (Identifier))) (Return (Identifier)))+} {+(Method (Identifier) (Params (Other "required_parameter" (Identifier))) (Return (Identifier)))+} {-(FieldDecl (Identifier) (NumberLiteral))-} {-(Method (Identifier) (Params (Other "required_parameter" (Identifier))) (Return (Identifier)))-} {-(Method (Identifier) (Params (Other "required_parameter" (Identifier))) (Return (Identifier)))-} {-(Method (Identifier) (Params (Other "required_parameter" (Identifier))) (Return (Identifier)))-})))