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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 write_cookies_to_cache(cj, username):
 """ Save RequestsCookieJar to disk in Mozilla's cookies.txt file format. This prevents us from repeated authentications on the accounts.coursera.org and class.coursera.org/class_name sites. """

    mkdir_p(PATH_COOKIES, 0o700)
    path = get_cookies_cache_path(username)
    cached_cj = cookielib.MozillaCookieJar()
    for cookie in cj:
        cached_cj.set_cookie(cookie)
    cached_cj.save(path)