code: def register_intent_parser(self, intent_parser, domain=0):
          
          if domain not in self.domains:
              self.register_domain(domain=domain)
          self.domains[domain].register_intent_parser(
              intent_parser=intent_parser)
docs: Register a intent parser with a domain.
  
          Args:
              intent_parser(intent): The intent parser you wish to register.
              domain(str): a string representing the domain you wish register the intent
                  parser to.