How to use the @lumino/dragdrop.Drag function in @lumino/dragdrop

// 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');

    // Create the cleanup callback.
    let cleanup = (() => {
      this._drag = null;
      tab.classList.remove('p-mod-hidden');
    });

    // Start the drag operation and cleanup when done.
    this._drag.start(clientX, clientY).then(cleanup);