def __init__()

in samplers.py [0:0]


    def __init__(self, dataset, num_replicas=None, rank=None, shuffle=True):
        if num_replicas is None:
            if not dist.is_available():
                raise RuntimeError(
                    "Requires distributed package to be available")
            num_replicas = dist.get_world_size()
        if rank is None:
            if not dist.is_available():
                raise RuntimeError(
                    "Requires distributed package to be available")
            rank = dist.get_rank()
        self.dataset = dataset
        self.num_replicas = num_replicas
        self.rank = rank
        self.epoch = 0
        self.num_samples = int(
            math.ceil(len(self.dataset) * 3.0 / self.num_replicas))
        self.total_size = self.num_samples * self.num_replicas
        # self.num_selected_samples = int(math.ceil(len(self.dataset) / self.num_replicas))
        self.num_selected_samples = int(math.floor(
            len(self.dataset) // 256 * 256 / self.num_replicas))
        self.shuffle = shuffle