@staticmethod
def _get_accumulators(outputs: dict):
    """
        builds and returns a dictionary containing a key for each step output.
        The outputs of each learning step is stored on this dictionary.
        :param outputs: A dictionary containing the learning step outputs.
        """
    accumulators = dict()
    for output_name in outputs.keys():
        accumulators[output_name] = list()
    return accumulators
