code: def setOpenIDNamespace(self, openid_ns_uri, implicit):
          
          if isinstance(openid_ns_uri, bytes):
              openid_ns_uri = str(openid_ns_uri, encoding="utf-8")
          if openid_ns_uri not in self.allowed_openid_namespaces:
              raise InvalidOpenIDNamespace(openid_ns_uri)
  
          self.namespaces.addAlias(openid_ns_uri, NULL_NAMESPACE, implicit)
          self._openid_ns_uri = openid_ns_uri
docs: Set the OpenID namespace URI used in this message.
  
          @raises InvalidOpenIDNamespace: if the namespace is not in
              L{Message.allowed_openid_namespaces}