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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def __check_logging_rules(configuration):
 """ Check that the logging values are proper """

    valid_log_levels = [
        'debug',
        'info',
        'warning',
        'error'
    ]
    if configuration['logging']['log_level'].lower() not in valid_log_levels:
        print('Log level must be one of {0}'.format(
            ', '.join(valid_log_levels)))
        sys.exit(1)