Set<String> queues = request.getQueues();
Set<String> tags = request.getApplicationTags();
long limit = request.getLimit();
LongRange start = request.getStartRange();
LongRange finish = request.getFinishRange();
ApplicationsRequestScope scope = request.getScope();
final Map<ApplicationId, RMApp> apps = rmContext.getRMApps();
Iterator<RMApp> appsIter;
// If the query filters by queues, we can avoid considering apps outside
// of those queues by asking the scheduler for the apps in those queues.