### Question:
MouseInputHandler extends MotionInputHandler<K> { @Override public boolean onScroll(@NonNull MotionEvent e1, @NonNull MotionEvent e2, float distanceX, float distanceY) { return !MotionEvents.isTouchpadScroll(e2); } MouseInputHandler(
            @NonNull SelectionTracker<K> selectionTracker,
            @NonNull ItemKeyProvider<K> keyProvider,
            @NonNull ItemDetailsLookup<K> detailsLookup,
            @NonNull OnContextClickListener onContextClickListener,
            @NonNull OnItemActivatedListener<K> onItemActivatedListener,
            @NonNull FocusDelegate<K> focusDelegate); @Override boolean onDown(@NonNull MotionEvent e); @Override boolean onScroll(@NonNull MotionEvent e1, @NonNull MotionEvent e2,
            float distanceX, float distanceY); @Override boolean onSingleTapUp(@NonNull MotionEvent e); @Override boolean onSingleTapConfirmed(@NonNull MotionEvent e); @Override boolean onDoubleTap(@NonNull MotionEvent e);  }### Answer:
@Test public void testScroll_shouldTrap() { mDetailsLookup.initAt(0); assertTrue(mInputDelegate.onScroll( null, mEvent.action(MotionEvent.ACTION_MOVE).primary().build(), -1, -1)); }
@Test public void testScroll_NoTrapForTwoFinger() { mDetailsLookup.initAt(0); assertFalse(mInputDelegate.onScroll( null, mEvent.action(MotionEvent.ACTION_MOVE).build(), -1, -1)); }