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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def notify(self, method_name, **cb_kwargs):
 """Call the callback method specified in ``method_name`` with parameters specified in ``cb_kwargs``. Method names can be one of: * on_train_begin * on_train_end * on_epoch_begin * on_epoch_end * on_batch_begin * on_batch_end """

        getattr(self, method_name)(self, **cb_kwargs)
        for _, cb in self.callbacks_:
            getattr(cb, method_name)(self, **cb_kwargs)