docs: def _detect_endian(cls, stream):
          """
          Return either BIG_ENDIAN or LITTLE_ENDIAN depending on the endian
          indicator found in the TIFF *stream* header, either 'MM' or 'II'.
          """
          stream.seek(0)
          endian_str = stream.read(2)
          return BIG_ENDIAN if endian_str == b'MM' else LITTLE_ENDIAN