public function addWorkspace($title)
    {
        $workspaces = $this->getWorkspaces();

        /** @var Workspace $workspace */
        $workspace = $this->getExtensions()->createElement($this, 'app:workspace');
        $workspace->addTitle($title);

        $workspaces[] = $workspace;
        $this->setCachedProperty('workspaces', $workspaces);

        return $workspace;
    }