code: def _set_session(self, username, realname, email, language):
          
          self._session.loggedin = True
          self._session.email = email
          self._session.username = username
          self._session.realname = realname
          self._session.language = language
          self._session.token = None
          if "lti" not in self._session:
              self._session.lti = None
docs: Init the session. Preserves potential LTI information.