How to use the @lumino/coreutils.MimeData function in @lumino/coreutils

private _onTabDetachRequested(sender: TabBar, args: TabBar.ITabDetachRequestedArgs): void {
    // Do nothing if a drag is already in progress.
    if (this._drag) {
      return;
    }

    // Release the tab bar's hold on the mouse.
    sender.releaseMouse();

    // Extract the data from the args.
    let { title, tab, clientX, clientY } = args;

    // Setup the mime data for the drag operation.
    let mimeData = new MimeData();
    let factory = () => title.owner;
    mimeData.setData('application/vnd.lumino.widget-factory', factory);

    // Create the drag image for the drag operation.
    let dragImage = tab.cloneNode(true) as HTMLElement;

    // Create the drag object to manage the drag-drop operation.
    this._drag = new Drag({
      mimeData, dragImage,
      proposedAction: 'move',
      supportedActions: 'move',
    });

    // Hide the tab node in the original tab.
    tab.classList.add('p-mod-hidden');