code: public Layer absorbHits () {
      return setHitTester(new Layer.HitTester() {
        public Layer hitTest (Layer layer, Point p) {
          Layer hit = hitTestDefault(p);
          return (hit == null) ? Layer.this : hit;
        }
        @Override public String toString () { return "<all>"; }
      });
    }
docs: Configures a hit tester for this layer which hits this layer any time a hit does not hit a
  child of this layer. This absorbs all hits that would otherwise propagate up to this layer's
  parent. Note that this does not do any calculations to determine whether the hit is within the
  bounds of this layer, as those may or may not be known. <em>All</em> all hits that are checked
  against this layer are absorbed.