def __query(self, query):
<EOL>xml = self.document.toxml()<EOL>return OneLogin_Saml2_Utils.query(fromstring(xml, forbid_dtd=True), query)<EOL>
Extracts a node from the DOMDocument (Logout Response Menssage)
:param query: Xpath Expresion
:type query: string
:return: The queried node
:rtype: DOMNodeList