'Initialize LM1BDataset reader.
Args:
filepattern: Dataset file pattern.
vocab: Vocabulary.'

def __init__(self, filepattern, vocab):

    self._vocab = vocab
    self._all_shards = tf.gfile.Glob(filepattern)
    tf.logging.info('Found    %d    shards    at    %s', len(self._all_shards), filepattern)
