code: public <T> Collection<? extends Callable<T>> wrap(Collection<? extends Callable<T>> tasks) {
          //no-op by default
          return tasks;
      }
docs: This method is invoked with the body of {@link AbstractExecutorServices#invokeAllAndCheckForExceptions(java.util.Collection)}
  
  It allows to wrap the tasks with some additional logic. For instance, Weld's {@link CommonForkJoinPoolExecutorServices}
  overrides this in order to set TCCL to null prior to execution.