def __init__(self, filename=None):
    """Initialize and read from a file, if provided.

    Args:
      filename: filename from which to read vocab. If None, do not load a
        vocab
    """
    self._alphabet = set()
    # self.filename = filename
    # if filename is not None:
    #   self._load_from_file(filename)
    super(SubwordTextEncoder, self).__init__()
Initialize and read from a file, if provided.

    Args:
      filename: filename from which to read vocab. If None, do not load a
        vocab
    
adalm/incr_bpe/text_encoder.py