@Override
 public void renderAreaSymbol(Bitmap symbol) {
   float[] centerPosition = GeometryUtils.calculateCenterOfBoundingBox(this.coordinates[0]);
   this.pointSymbols.add(
       new SymbolContainer(
           symbol,
           centerPosition[0] - (symbol.getWidth() >> 1),
           centerPosition[1] - (symbol.getHeight() >> 1)));
 }
 @Override
 public void renderAreaCaption(String caption, float verticalOffset, Paint paint, Paint stroke) {
   float[] centerPosition = GeometryUtils.calculateCenterOfBoundingBox(this.coordinates[0]);
   this.areaLabels.add(
       new PointTextContainer(caption, centerPosition[0], centerPosition[1], paint, stroke));
 }