code: public static BufferedImage renderDOTImage(Reader dotReader) throws IOException {
          InputStream pngIs = runDOT(dotReader, "png");
          BufferedImage img = ImageIO.read(pngIs);
          pngIs.close();
  
          return img;
      }
docs: Reads a DOT description from a reader and returns the PNG rendering result as a {@link BufferedImage}.
  
  @param dotReader
  the reader from which to read the description
  
  @return the rendering result
  
  @throws IOException
  if reading from the reader fails, or the pipe to the DOT process breaks.