code: def save_history(self, f):
          
          # TODO: Remove warning in a future release
          warnings.warn(
              "save_history is deprecated and will be removed in the next "
              "release, please use save_params with the f_history keyword",
              DeprecationWarning)
  
          self.history.to_file(f)
docs: Saves the history of ``NeuralNet`` as a json file. In order
          to use this feature, the history must only contain JSON encodable
          Python data structures. Numpy and PyTorch types should not
          be in the history.
  
          Parameters
          ----------
          f : file-like object or str
  
          Examples
          --------
  
          >>> before = NeuralNetClassifier(mymodule)
          >>> before.fit(X, y, epoch=2) # Train for 2 epochs
          >>> before.save_params('path/to/params')
          >>> before.save_history('path/to/history.json')
          >>> after = NeuralNetClassifier(mymodule).initialize()
          >>> after.load_params('path/to/params')
          >>> after.load_history('path/to/history.json')
          >>> after.fit(X, y, epoch=2) # Train for another 2 epochs