code: @SuppressWarnings("static-method")
  	protected <T> Callable<T> createTask(Callable<T> callable) {
  		if (callable instanceof JanusCallable<?>) {
  			return callable;
  		}
  		return new JanusCallable<>(callable);
  	}
docs: Create a task with the given callable.
  
  @param <T> the type of the returned value.
  @param callable the callable.
  @return the task.