Extracts nodes that match the query from the Response

        :param query: Xpath Expresion
        :type query: String

        :param tagid: Tag ID
        :type query: String

        :returns: The queried nodes
        :rtype: list

def __query(self, query, tagid=None):
        """
        Extracts nodes that match the query from the Response

        :param query: Xpath Expresion
        :type query: String

        :param tagid: Tag ID
        :type query: String

        :returns: The queried nodes
        :rtype: list
        """
        if self.encrypted:
            document = self.decrypted_document
        else:
            document = self.document
        return OneLogin_Saml2_Utils.query(document, query, None, tagid)