{+(Program
  (Class
    (Identifier)
    (Assignment
      (Identifier)
      (NumberLiteral))
    (Method
      (Identifier)
      (Params
        (Identifier))
      (Return
        (Identifier)))
    (Method
      (Identifier)
      (Params
        (Identifier))
      (Return
        (Identifier)))
    (Method
      (Identifier)
      (Params
        (Identifier))
      (Return
        (Identifier)))))+}