public function createMysqlUser($serverId, array $data, $wait = true)
    {
        $user = $this->post("servers/$serverId/mysql-users", $data)['user'];

        if ($wait) {
            return $this->retry($this->getTimeout(), function () use ($serverId, $user) {
                $user = $this->mysqlUser($serverId, $user['id']);

                return $user->status == 'installed' ? $user : null;
            });
        }

        return new MysqlUser($user + ['server_id' => $serverId], $this);
    }