code: def args_wrapper(*args):
      
      out = defaultdict(list)
      for callback in args:
          callback_args = callback.callback_args()
          for k, v in callback_args.items():
              out[k].append(v)
      return dict(out)
docs: Generates callback arguments for model.fit()
      for a set of callback objects.
      Callback objects like PandasLogger(), LiveLearningCurve()
      get passed in.  This assembles all their callback arguments.