(self, metadata)
Take actions at the beginning of the training.

        Parameters
        ----------
        metadata : dict
            Dictionary that is going to be populated with relevant data within `Run.launch`.
Take actions at the beginning of the training.
Take actions at the beginning of the training .
def on_train_begin(self, metadata):
        """Take actions at the beginning of the training.

        Parameters
        ----------
        metadata : dict
            Dictionary that is going to be populated with relevant data within `Run.launch`.
        """
        pass
def on_train_begin ( self , metadata ) : pass