CancellationInterface.php

<?php

declare (strict_types=1);
namespace OpenTelemetry\SDK\Common\Future;

use Closure;
use Throwable;
interface CancellationInterface {
    
    /**
     * @param Closure(Throwable): void $callback
     */
    public function subscribe(Closure $callback) : string;
    public function unsubscribe(string $id) : void;

}