code: public double getArea() {
  		double area = 0;
  		if (!isEmpty()) {
  			area = exteriorRing.getArea();
  			if (interiorRings != null) {
  				for (LinearRing interiorRing : interiorRings) {
  					area -= interiorRing.getArea();
  				}
  			}
  		}
  		return area;
  	}
docs: Return the shell area minus holes areas.