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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 add_site_element(self, element):
 """ Add a site element or list of elements to this VPN. :param list element: list of Elements or href's of vpn site elements :type element: list(str,Network) :raises UpdateElementFailed: fails due to reason :return: None """

        element = element_resolver(element)
        self.data['site_element'].extend(element)
        self.update()