async def load_message(self, msg_type, msg=None):
msg = msg_type() if msg is None else msg<EOL>fields = msg_type.f_specs() if msg_type else msg.__class__.f_specs()<EOL>for field in fields:<EOL><INDENT>await self.message_field(msg, field)<EOL><DEDENT>return msg<EOL>
Loads message if the given type from the reader.
Supports reading directly to existing message.

:param msg_type:
:param msg:
:return: