def next(self):
    """Returns the next input from this input reader as a key, value pair.

    Returns:
      The next input from this input reader.
    """
    raise NotImplementedError(self.__class__ % "next() not implemented in %s")
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/ext/mapreduce/input_readers.py/InputReader.next/swapped operands of `%`