'Grab the metadata attached to the tag'

def _deserialize(self, chunks):

    self._tagger = None
    self._tag_time = None
    self._tag_timezone = None
    self._tag_timezone_neg_utc = False
    for (field, value) in _parse_message(chunks):
        if (field == _OBJECT_HEADER):
            self._object_sha = value
        elif (field == _TYPE_HEADER):
            obj_class = object_class(value)
            if (not obj_class):
                raise ObjectFormatException(('Not    a    known    type:    %s' % value))
            self._object_class = obj_class
        elif (field == _TAG_HEADER):
            self._name = value
        elif (field == _TAGGER_HEADER):
            try:
                sep = value.index('>    ')
            except ValueError:
                self._tagger = value
                self._tag_time = None
                self._tag_timezone = None
                self._tag_timezone_neg_utc = False
            else:
                self._tagger = value[0:(sep + 1)]
                try:
                    (timetext, timezonetext) = value[(sep + 2):].rsplit('    ', 1)
                    self._tag_time = int(timetext)
                    (self._tag_timezone, self._tag_timezone_neg_utc) = parse_timezone(timezonetext)
                except ValueError as e:
                    raise ObjectFormatException(e)
        elif (field is None):
            self._message = value
        else:
            raise ObjectFormatException(('Unknown    field    %s' % field))
