def _existing_file_path_option(option_name, option_value):
    file_path = FilePath(option_value)
    if not file_path.exists():
        raise UsageError(
            u"Problem with --{}. File does not exist: '{}'.".format(
                option_name, file_path.path
            )
        )
    return file_path
@see: twisted.names.client.lookupIPV6Address
dataset/ETHPy150Open ClusterHQ/flocker/admin/cleanup.py/_existing_file_path_option--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/names/common.py/ResolverBase.lookupIPV6Address