en the editor is initialized.
        if (!$popup) $popup = initPopup()

        // Set the editor toolbar as the popup's container.
        editor.popups.setContainer('customPlugin.popup', editor.$tb)

        // If the editor is not displayed when a toolbar button is pressed, then set BODY as the popup's container.
        // editor.popups.setContainer('customPlugin.popup', $('body'));

        // Trigger refresh for the popup.
        // editor.popups.refresh('customPlugin.popup');

        // This custo