@Override
 protected List<I> execute(org.opencb.commons.run.Task<I> task, List<I> batch) {
   try {
     task.apply(batch);
   } catch (IOException e) {
     e.printStackTrace();
   }
   return batch;
 }
 @Override
 protected void post() {
   for (org.opencb.commons.run.Task<I> task : tasks) {
     task.post();
   }
 }