(Program
  (Function
    (Empty)
    (Empty)
    (Empty)
    (RequiredParameter
      (Empty)
      (Empty)
      (Empty)
      (Assignment
        (Identifier)
        (Empty)))
    (RequiredParameter
      (Empty)
      (Empty)
      (Empty)
      (Assignment
        (Identifier)
        (Empty)))
    (Statements
      (Return
      { (Identifier)
      ->(Identifier) }))))