Workerman定时器精度问题

<?php
use Workerman\Lib\Timer;
use Workerman\Worker;

require_once "./vendor/autoload.php";

$worker = new Worker();
$worker->onWorkerStart = function($worker){
    Timer::add(0.001,function() use ($worker){
        echo microtime(true).PHP_EOL;
    });
};
Worker::runAll();