def __init__(self, name, full_name, index, containing_service,
               input_type, output_type, options=None, serialized_options=None,
               create_key=None):
    """The arguments are as described in the description of MethodDescriptor
    attributes above.

    Note that containing_service may be None, and may be set later if necessary.
    """
    if create_key is not _internal_create_key:
      _Deprecated('MethodDescriptor')

    super(MethodDescriptor, self).__init__(
        options, serialized_options, 'MethodOptions')
    self.name = name
    self.full_name = full_name
    self.index = index
    self.containing_service = containing_service
    self.input_type = input_type
    self.output_type = output_type
The arguments are as described in the description of MethodDescriptor
    attributes above.

    Note that containing_service may be None, and may be set later if necessary.
    
deps/protobuf/python/google/protobuf/descriptor.py