docs: def _get_provider_session(self, session_name, proxy=None):
          """Gets the session for the provider"""
          agent_key = self._get_agent_key(proxy)
          if session_name in self._provider_sessions[agent_key]:
              return self._provider_sessions[agent_key][session_name]
          else:
              session = self._instantiate_session('get_' + session_name, self._proxy)
              self._set_gradebook_view(session)
              if self._session_management != DISABLED:
                  self._provider_sessions[agent_key][session_name] = session
              return session