boolean hasJobEnded() {
    int lUnitsPending = mProcessUnits.size();
    for (ProcessControlUnit lUnit : mProcessUnits) {
      if (lUnit.hasResult()) {
        lUnitsPending--;
      }
    }

    return lUnitsPending == 0;
  }
 void stop() {
   for (ProcessControlUnit lUnit : mProcessUnits) {
     lUnit.stop();
   }
 }