code: void refresh(final DFSContent content) {
      if (this.sviewer != null) {
        Display.getDefault().asyncExec(new Runnable() {
          public void run() {
            DFSContentProvider.this.sviewer.refresh(content);
          }
        });
  
      } else {
        refresh();
      }
    }
docs: Ask the viewer to refresh a single element
  
  @param content what to refresh