def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def message_data(self):
        if self.proto_view == 0:
            return self.message.plain_bits_str
        elif self.proto_view == 1:
            return self.message.plain_hex_str
        elif self.proto_view == 2:
            return self.message.plain_ascii_str
        else:
            return None