}
// TODO Does this move to the client in case of work-preserving recovery.
TokenCache.setSessionToken(sessionToken, dagCredentials);
// create single dag
DAGImpl newDag =
new DAGImpl(dagId, dagConf, dagPB, dispatcher.getEventHandler(),
taskAttemptListener, dagCredentials, clock,
appMasterUgi.getShortUserName(),
taskHeartbeatHandler, context);
try {