(Program
  (ExpressionStatements
    (Function
      (Identifier)
      (Params
        (Other "required_parameter"
          (Identifier))
        (Other "required_parameter"
          (Identifier)))
      (DoWhile
        (ExpressionStatements
          (ExpressionStatements
            (FunctionCall
              (Identifier)
            { (Identifier)
            ->(Identifier) })))
      { (Identifier)
      ->(Identifier) }))))