private void CloseTabDocument(ITabDocument document)
 {
     if (document is IWorkbenchDocument)
     {
         (document as IWorkbenchDocument).CloseDocument();
     }
     else
     if (document is MySQL.Forms.AppViewDockContent)
     {
         MySQL.Forms.AppViewDockContent content = document as MySQL.Forms.AppViewDockContent;
         content.CloseDocument();
     }
 }
        private void tabControl_TabClosing(object sender, TabClosingEventArgs e)
        {
            ITabDocument document = (sender as FlatTabControl).DocumentFromPage(e.page);

            if (document is IWorkbenchDocument)
            {
                e.canClose = (document as IWorkbenchDocument).CanCloseDocument();
            }
            else
            if (document is MySQL.Forms.AppViewDockContent)
            {
                MySQL.Forms.AppViewDockContent content = document as MySQL.Forms.AppViewDockContent;
                e.canClose = content.CanCloseDocument();
            }
        }