def METHOD_NAME(self, samples):
    """Merge a list of samples to form a mini-batch.
    Args:
        samples (List[dict]): samples to collate
    Returns:
        dict: a mini-batch suitable for forwarding with a Model
    """
    if len(samples) == 0:
        return {}
    sample = OrderedDict()
    for k, ds in self.defn.items():
        try:
            sample[k] = ds.METHOD_NAME([s[k] for s in samples])
        except NotImplementedError:
            sample[k] = default_collate([s[k] for s in samples])
    return _unflatten(sample)