code: public double getLength() {
  		double length = 0;
  		if (!isEmpty()) {
  			length = exteriorRing.getLength();
  			if (interiorRings != null) {
  				for (LinearRing interiorRing : interiorRings) {
  					length += interiorRing.getLength();
  				}
  			}
  		}
  		return length;
  	}
docs: Return the total length of all rings.