create image always returning null

Hi All,


IOObject io=ioResult.getElementAt(0);
TreeModel model=(TreeModel) ioResult.getElementAt(0);
  Renderer createRenderer = RendererService.createRenderer(io, "Graph View");
      Component visualizationComponent=  createRenderer.getVisualizationComponent(io, ioResult);
      System.out.println(visualizationComponent.isDisplayable());
      Image createImage = visualizationComponent.createImage(100, 100);
        Graphics graphics = createImage.getGraphics();


visualizationComponent.isDisplayable()....false.
here createImage always returning null
what could be the reason?

thanks in advance.