code: String getWhereTaskletWasScheduledTo(final int taskletId) {
      for (final Map.Entry<String, VortexWorkerManager> entry : runningWorkers.entrySet()) {
        final String workerId = entry.getKey();
        final VortexWorkerManager vortexWorkerManager = entry.getValue();
        if (vortexWorkerManager.containsTasklet(taskletId)) {
          return workerId;
        }
      }
      return null;
    }
docs: Find where a tasklet is scheduled to.
  @param taskletId id of the tasklet in question
  @return id of the worker (null if the tasklet was not scheduled to any worker)