code: def get_id(request):
          
          if isinstance(request, etree._Element):
              elem = request
          else:
              if isinstance(request, Document):
                  request = request.toxml()
              elem = fromstring(request, forbid_dtd=True)
          return elem.get('ID', None)
docs: Returns the ID of the Logout Request
          :param request: Logout Request Message
          :type request: string|DOMDocument
          :return: string ID
          :rtype: str object