code: def extend(self, other):
          
          overlap = [key for key in other.defaults if key in self.defaults]
          if overlap:
              raise ValueError(
                  "Duplicate hyperparameter(s): %s" % " ".join(overlap))
          new = dict(self.defaults)
          new.update(other.defaults)
          return HyperparameterDefaults(**new)
docs: Return a new HyperparameterDefaults instance containing the
          hyperparameters from the current instance combined with
          those from other.
  
          It is an error if self and other have any hyperparameters in
          common.