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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 find_ca_bundle():
 """Return an existing CA bundle path, or None"""

    extant_cert_paths = filter(os.path.isfile, cert_paths)
    return (
        get_win_certfile()
        or next(extant_cert_paths, None)
        or _certifi_where()
    )