code: public function add(InvokerInterface $invoker, $taskArgs = [])
      {
          $taskArgs = (is_array($taskArgs) ? $taskArgs : array_slice(func_get_args(), 1));
  
          array_unshift($this->tasks, compact('invoker', 'taskArgs'));
  
          return $this;
      }
docs: Add callbacks or \Closure into task queueing stack.
  
  @param InvokerInterface $invoker
  @param array $taskArgs The callback or Closure arguments.
  @return TaskQueueInterface