code: protected <V> RunnableScheduledFuture<V> decorateTask(
          Callable<V> callable, RunnableScheduledFuture<V> task) {
          return task;
      }
docs: Modifies or replaces the task used to execute a callable.
  This method can be used to override the concrete
  class used for managing internal tasks.
  The default implementation simply returns the given task.
  
  @param callable the submitted Callable
  @param task the task created to execute the callable
  @param <V> the type of the task's result
  @return a task that can execute the callable
  @since 1.6