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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 get_metadata(url, validate_cert=True):
 """ Gets the metadata XML from the provided URL :param url: Url where the XML of the Identity Provider Metadata is published. :type url: string :param validate_cert: If the url uses https schema, that flag enables or not the verification of the associated certificate. :type validate_cert: bool :returns: metadata XML :rtype: string """

        valid = False
        if validate_cert:
            response = urllib2.urlopen(url)
        else:
            ctx = ssl.create_default_context()
            ctx.check_hostname = False
            ctx.verify_mode = ssl.CERT_NONE
            response = urllib2.urlopen(url, context=ctx)
        xml = response.read()

        if xml:
            try:
                dom = fromstring(xml, forbid_dtd=True)
                idp_descriptor_nodes = OneLogin_Saml2_Utils.query(dom, '//md:IDPSSODescriptor')
                if idp_descriptor_nodes:
                    valid = True
            except Exception:
                pass

        if not valid:
            raise Exception('Not valid IdP XML found from URL: %s' % (url))

        return xml