private double getScale(FileFormatOption fileFormatOption, final Dimension2D dim) {
   final double scale;
   final Scale diagScale = diagram.getScale();
   if (diagScale == null) {
     scale = diagram.getDpiFactor(fileFormatOption);
   } else {
     scale = diagScale.getScale(dim.getWidth(), dim.getHeight());
   }
   return scale;
 }