(Program
  (Send
    (Identifier)
    (Send
      (Identifier))
    (Function
      (Empty)
      ([])))
  (Send
    (Send
      (Identifier))
    (Identifier)
    (Function
      (Empty)
      (Identifier)
      (Identifier)
      (Identifier)
      ([])))
  (Send
    (Identifier)
    (Send
      (Identifier))
    (Function
      (Empty)
      (Identifier)
      ([])))
  (Identifier))