:meth:`.WMessengerOnionLayerProto.process` implementation

def process(self, envelope, session, mode=None, **kwargs):
		""" :meth:`.WMessengerOnionLayerProto.process` implementation
		"""
		if mode is None:
			raise RuntimeError('"mode" argument must be specified for this object')

		if isinstance(mode, self.__mode_cls) is False:
			raise TypeError('Invalid "mode" argument')

		return self._process(envelope, session, mode, **kwargs)