code: def _do_logoff(self):
          
          session_uri = '/api/sessions/this-session'
          self.delete(session_uri, logon_required=False)
          self._session_id = None
          self._session = None
          self._headers.pop('X-API-Session', None)
docs: Log off, unconditionally.
  
          Raises:
  
            :exc:`~zhmcclient.ServerAuthError`
            :exc:`~zhmcclient.ConnectionError`
            :exc:`~zhmcclient.ParseError`
            :exc:`~zhmcclient.HTTPError`