<?php
declare(strict_types=1);
namespace GuzzleHttp\Promise;
interface TaskQueueInterface
{
/**
* Returns true if the queue is empty.
*/
public function isEmpty(): bool;
/**
* Adds a task to the queue that will be executed the next time run is
* called.
*/
public function add(callable $task): void;
/**
* Execute all of the pending task in the queue.
*/
public function run(): void;
}