delay example

if (null !== $throttleWatcher) {
                Loop::cancel($throttleWatcher);
            }

            $pause = $pauseDeferred->promise();

            if ($duration <= 0) {
                $deferred = $pauseDeferred;
                $pauseDeferred = new Deferred();
                $deferred->resolve();
            } else {
                $throttleWatcher = Loop::delay(ceil(1000 * $duration), static function D) use (&$pauseDeferred) {
                    $deferred = $pauseDeferred;
                    $pauseDeferred = new Deferred();
                    $deferred->resolve();
                });
            }
        };

        $multi->lastTimeout = null;
        $multi->openHandles[$id] = $id;
        ++$multi->responseCount;