private Polygon execute(Polygon polygon) {
Polygon result = null;
if (index.getInteriorRingIndex() >= 0) {
interiorRing = polygon.getInteriorRingN(index.getInteriorRingIndex());
RemoveRingOperation op = new RemoveRingOperation(index.getInteriorRingIndex());
result = (Polygon) op.execute(polygon);
}
if (result != null) {
return result;
}
return polygon;