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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 get_configuration_file():
 """ return jenks configuration file """

    path = os.path.abspath(os.curdir)
    while path != os.sep:
        config_path = os.path.join(path, CONFIG_FILE_NAME)
        if os.path.exists(config_path):
            return config_path
        path = os.path.dirname(path)
    return None