class_docstr: Abstract base class for protocol messages.
  
  Protocol message classes are almost always generated by the protocol
  compiler.  These generated types subclass Message and implement the methods
  shown below.
docstr: Returns the UnknownFieldSet.
  
  Returns:
    UnknownFieldSet: The unknown fields stored in this message.
docstr_tok: ["Returns","the","UnknownFieldSet",".","Returns",":","UnknownFieldSet",":","The","unknown","fields","stored","in","this","message","."]
code: def UnknownFields(self):
      """Returns the UnknownFieldSet.
  
      Returns:
        UnknownFieldSet: The unknown fields stored in this message.
      """
      raise NotImplementedError
  
label_desc: Use image node_id 22 for calling the Message obj's underlying member method code with example usage: obj.UnknownFields() without return types