docs: private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
  		in.defaultReadObject();
  		final N me = toN();
  		if (this.nNorthEast != null) {
  			this.nNorthEast.setParentNodeReference(me, false);
  		}
  		if (this.nNorthWest != null) {
  			this.nNorthWest.setParentNodeReference(me, false);
  		}
  		if (this.nSouthEast != null) {
  			this.nSouthEast.setParentNodeReference(me, false);
  		}
  		if (this.nSouthWest != null) {
  			this.nSouthWest.setParentNodeReference(me, false);
  		}
  	}