wear/src/main/java/androidx/wear/widget/SwipeDismissFrameLayout.java
public void addCallback(Callback callback) {
        if (callback == null) {
            throw new NullPointerException("addCallback called with null callback");
        }
        mCallbacks.add(callback);
    }
/** Adds a callback for dismissal. */
Adds a callback for dismissal.
Adds a callback for dismissal .
public void addCallback(Callback callback) {
        if (callback == null) {
            throw new NullPointerException("addCallback called with null callback");
        }
        mCallbacks.add(callback);
    }
public void addCallback ( Callback callback ) { if ( callback == null ) { throw new NullPointerException ( "addCallback called with null callback" ) ; } mCallbacks . add ( callback ) ; }
Adds a callback for dismissal.
Adds a callback for dismissal .