workerman websocket怎么群发消息

$worker = new Worker('Websocket://0.0.0.0:8484');
// 进程启动时设置一个定时器，定时向所有客户端连接发送数据
$worker->onMessage= function($connection, $data)use($worker)
{
    // 遍历当前进程所有的客户端连接，发送
    foreach($worker->connections as $connection)
    {
        $connection->send('.....');
    }
};