code: def check_valid_keys(self, obj):
          
          invalid_keys = [
              x for x in obj if x not in self.defaults
          ]
          if invalid_keys:
              raise ValueError(
                  "No such model parameters: %s. Valid parameters are: %s"
                  % (" ".join(invalid_keys),
                      " ".join(self.defaults)))
docs: Given a dict of hyperparameter settings, throw an exception if any
          keys are not defined in this HyperparameterDefaults instance.