React\Promise\FulfilledPromise::then PHP Метод

    public function then(callable $onFulfilled = null, callable $onRejected = null)
    {
        if (null === $onFulfilled) {
            return $this;
        }
        return new Promise(function (callable $resolve, callable $reject) use($onFulfilled) {
            queue()->enqueue(function () use($resolve, $reject, $onFulfilled) {
                try {
                    $resolve($onFulfilled($this->value));
                } catch (\Throwable $exception) {
                    $reject($exception);
                } catch (\Exception $exception) {
                    $reject($exception);
                }
            });
        });
    }