code: public GeoPolygon addHoles(List<List<GeoPoint>> holes) {
  		Contracts.assertNotNull( holes, "holes" );
  		this.rings.addAll( holes );
  		return this;
  	}
docs: Adds new holes to the polygon.
  
  @param holes holes, must be contained in the exterior ring and must not overlap or
  intersect another hole
  @return this for chaining