def __init__(self, _body_message_class=message_types.VoidMessage, **kwargs):
self.body_message_class = _body_message_class<EOL>self.parameters_message_class = type('<STR_LIT>',<EOL>(messages.Message,), kwargs)<EOL>
Constructor for ResourceContainer.

        Stores a request body message class and attempts to create one from the
        keyword arguments passed in.

        Args:
          _body_message_class: A keyword argument to be treated like a positional
              argument. This will not conflict with the potential names of fields
              since they can't begin with underscore. We make this a keyword
              argument since the default VoidMessage is a very common choice given
              the prevalence of GET methods.
          **kwargs: Keyword arguments specifying field names (the named arguments)
              and instances of ProtoRPC fields as the values.