(Statements
  (Hash
    (Method
      (Empty)
      (Empty)
      (Empty)
      (Empty)
    { (Identifier)
    ->(Identifier) }
      (RequiredParameter
        (Empty)
        (Empty)
        (Identifier)
        (Empty))
      (RequiredParameter
        (Empty)
        (Empty)
        (Identifier)
        (Empty))
      (StatementBlock
        (Return
        { (Plus
          {-(Identifier)-}
          {-(Identifier)-})
        ->(Minus
          {+(Identifier)+}
          {+(Identifier)+}) })))))