docs: def _rle_decode(data):
      """
      Decodes run-length-encoded `data`.
      """
      if not data:
          return data
  
      new = b''
      last = b''
      for cur in data:
          if last == b'\0':
              new += last * cur
              last = b''
          else:
              new += last
              last = bytes([cur])
  
      return new + last