code: def as_text(bytes_or_text, encoding='utf-8'):
      
      if isinstance(bytes_or_text, _six.text_type):
          return bytes_or_text
      elif isinstance(bytes_or_text, bytes):
          return bytes_or_text.decode(encoding)
      else:
          raise TypeError('Expected binary or unicode string, got %r' % bytes_or_text)
docs: Returns the given argument as a unicode string.
      Args:
        bytes_or_text: A `bytes`, `str, or `unicode` object.
        encoding: A string indicating the charset for decoding unicode.
      Returns:
        A `unicode` (Python 2) or `str` (Python 3) object.
      Raises:
        TypeError: If `bytes_or_text` is not a binary or unicode string.