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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 enable_cache():
 """Enable requests library cache."""

    try:
        import requests_cache
    except ImportError as err:
        sys.stderr.write('Failed to enable cache: {0}\n'.format(str(err)))
        return
    if not os.path.exists(CACHE_DIR):
        os.makedirs(CACHE_DIR)
    requests_cache.install_cache(CACHE_FILE)