async def dump_message_field(obj, msg, field, field_archiver=None):
fname, ftype, params = field[<NUM_LIT:0>], field[<NUM_LIT:1>], field[<NUM_LIT:2>:]<EOL>fvalue = getattr(msg, fname, None)<EOL>field_archiver = field_archiver if field_archiver else dump_field<EOL>return await field_archiver(eref(obj, fname, True), fvalue, ftype, params)<EOL>
Dumps a message field to the object. Field is defined by the message field specification.

:param obj:
:param msg:
:param field:
:param field_archiver:
:return: