fix for fill="transparent" for Batik renderer

Signed-off-by: Stefan Niederhauser <[email protected]>

Author: nidi3

graphviz-java/src/main/java/guru/nidi/graphviz/engine/BatikRasterizer.java

@@ -30,7 +30,7 @@ class BatikRasterizer extends SvgRasterizer {
     @Override
     public BufferedImage doRasterize(Graphviz graphviz, @Nullable Consumer<Graphics2D> graphicsConfigurer, String svg) {
         final BufferedImage[] image = new BufferedImage[1];
-        final TranscoderInput in = new TranscoderInput(new StringReader(svg));
+        final TranscoderInput in = new TranscoderInput(new StringReader(svg.replace("fill=\"transparent\"", "fill-opacity=\"0\"")));
         try {
             final TranscoderOutput out = new TranscoderOutput(new OutputStream() {
                 @Override