docs: def read_bytes(fh, byteorder, dtype, count, offsetsize):
      """Read tag data from file and return as byte string."""
      dtype = 'B' if dtype[-1] == 's' else byteorder+dtype[-1]
      count *= numpy.dtype(dtype).itemsize
      data = fh.read(count)
      if len(data) != count:
          log.warning('read_bytes: failed to read all bytes (%i < %i)',
                      len(data), count)
      return data