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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 request_get_next(request, default_next):
 """ get next url form request order: POST.next GET.next HTTP_REFERER, default_next """

    next_url = request.POST.get('next')\
        or request.GET.get('next')\
        or request.META.get('HTTP_REFERER')\
        or default_next
    return next_url