text: # Copyright (c) Facebook, Inc. and its affiliates.
  #
  # This source code is licensed under the MIT license found in the
  # LICENSE file in the root directory of this source tree.
  
  from . import BaseWrapperDataset
  
  
  class ListDataset(BaseWrapperDataset):
      def __init__(self, dataset, sizes=None):
          super().__init__(dataset)
          self._sizes = sizes
  
      def __iter__(self):
          for x in self.dataset:
              yield x
  
      def collater(self, samples):
          return samples
  
      @property
      def sizes(self):
          return self._sizes
  
      def num_tokens(self, index):
          return self.sizes[index]
  
      def size(self, index):
          return self.sizes[index]
  
      def set_epoch(self, epoch):
          pass
  