<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def register_intent_parser(self, intent_parser):
 """ "Enforce" the intent parser interface at registration time. Args: intent_parser(intent):
 Intent to be registered. Raises: ValueError: on invalid intent """

        if hasattr(intent_parser, 'validate') and callable(intent_parser.validate):
            self.intent_parsers.append(intent_parser)
        else:
            raise ValueError("%s is not an intent parser" % str(intent_parser))