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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 url_rule(blueprint_or_app, rules, endpoint=None, view_func=None, **options):
 """ Add one or more url rules to the given Flask blueprint or app. :param blueprint_or_app: Flask blueprint or app :param rules: a single rule string or a list of rules :param endpoint: endpoint :param view_func: view function :param options: other options """

    for rule in to_list(rules):
        blueprint_or_app.add_url_rule(rule,
                                      endpoint=endpoint,
                                      view_func=view_func,
                                      **options)