@Override
      public void apply(StatsTask statsTask) {
        if (statsTask.getWork().isAggregating()) {
          statsTasks.put(statsTask.getWork().getAggKey(), statsTask);
        }
      }
Checks if a task can be launched.

@param tsk
         the task to be checked
@return true if the task is launchable, false otherwise
ql/src/java/org/apache/hadoop/hive/ql/TaskQueue.java