src/Socket/Enhanced/Controller.php
static function send($data, $client_id = null) {
        return $client_id ? Gateway::sendToClient($client_id, $data) : Gateway::sendToCurrentClient($data);
    }
static function send($data, $client_id = null) {
        return $client_id ? Gateway::sendToClient($client_id, $data) : Gateway::sendToCurrentClient($data);
    }
向客户端发送数据

@param $data
@param $client_id
@return bool