code: public byte[] getGraph(String dot_source, String type)
  			throws GraphVizException
  	{
  		File dot;
  		byte[] img_stream = null;
  		try
  		{
  			dot = writeDotSourceToFile(dot_source);
  			if (dot != null)
  			{
  				img_stream = get_img_stream(dot, type);
  				if (!dot.delete())
  				{
  					throw new GraphVizException("Warning: "
  							+ dot.getAbsolutePath() + " could not be deleted!");
  				}
  				return img_stream;
  			}
  			return null;
  
  		} catch (IOException ioe)
  		{
  			return null;
  		}
  
  	}
docs: Returns the graph as an image in binary format.
  
  @param dot_source
  Source of the graph to be drawn.
  @param type
  Type of the output image to be produced, e.g.: gif, dot, fig, pdf, ps, svg, png.
  @return A byte array containing the image of the graph.
  @throws GraphVizException