code: public void intersect (Area area) {
          if (area == null) {
              return;
          } else if (isEmpty() || area.isEmpty()) {
              reset();
              return;
          }
  
          if (isPolygonal() && area.isPolygonal()) {
              intersectPolygon(area);
          } else {
              intersectCurvePolygon(area);
          }
  
          if (areaBoundsSquare() < GeometryUtil.EPSILON) {
              reset();
          }
      }
docs: Intersects the supplied area with this area.