android - How do I close the app on chrome custom tab close -

i want app close when user closes custom tab.

i experimented with:

public interface connectioncallback {         /**          * called when service connected.          */         void oncustomtabsconnected();          /**          * called when service disconnected.          */         void oncustomtabsdisconnected();     } 

but wont work.

p.s. new android/java