Since this is only a commited patch taken from here, the thing to notice is this:
onTap = ovl.getClass().getMethod("onTap", GeoPoint.class, MapView.class);
Therefore, implementing an onTap() method in an Overlay item should yield expected results.
Example:
public abstract class ResponsiveOverlay implements Overlay {
public void onTap(GeoPoint geoPoint) {
}
// ...
}