def skip_random_fraction_when_training(self):
    """Skip a random number of examples at the beginning of training."""
    # Skip a random fraction at the beginning of the stream.  The skip is
    # essential for synchronous highly-parallel training to avoid multiple
    # replicas reading the same data in lock-step. So keep this true unless
    # you have a very specific setting in which it needs to be turned off.
    return True
Skip a random number of examples at the beginning of training.
tensor2tensor/data_generators/problem.py