docs: def parse_byte_range(byte_range, min_byte=0, max_byte=sys.maxint):
      """
      Parse and validate a byte range. A byte range is a tuple of (begin, end)
      indices. `begin' should be smaller than `end', and both should fall within
      the `min_byte' and `max_byte'.
  
      In case of a violation, a `ValueError` is raised.
      """
  
      if not byte_range:
          return min_byte, max_byte
  
      begin = byte_range[0] or min_byte
      end = byte_range[1] or max_byte
  
      if end < begin:
          raise ValueError("End before begin")
  
      if begin < min_byte:
          raise ValueError("Begin smaller than min")
  
      if end > max_byte:
          raise ValueError("End larger than max")
  
      return begin, end