def METHOD_NAME(self, first_batch_idx: int, checkpoint_uuid: Optional[str]) -> None:
    """
    Runs before training, validation, or building dataloaders.
    Arguments:
        first_batch_idx (int):  The first batch index to be trained.  If the trial has already
            completed some amount of training in a previous allocation on the cluster, this will
            be nonzero.
        checkpoint_uuid (str or None):  The checkpoint from which weight, optimizer state, etc.
            will be loaded.  When ``first_batch_idx > 0`` this will contain the uuid of the
            most recent checkpoint saved by this trial.  Otherwise, it will contain the uuid of
            the checkpoint from which this trial was configured to warm start from (via
            ``source_trial_id`` or ``source_checkpoint_uuid`` in the searcher config), or None
            if no warm start was configured.
    """
    pass