public void testAddOnComputeInternalInsetsListener() {
    final ListView lv1 = (ListView) mActivity.findViewById(R.id.listview1);
    mViewTreeObserver = lv1.getViewTreeObserver();

    MockOnComputeInternalInsetsListener listener = new MockOnComputeInternalInsetsListener();
    mViewTreeObserver.addOnComputeInternalInsetsListener(listener);
  }
 /**
  * Make the touchable area of this popup be the area specified by mTouchableRegion. This should
  * be called after the popup window has been dismissed (dismiss/hide) and is probably being
  * re-shown with a new content root view.
  */
 private void setTouchableSurfaceInsetsComputer() {
   ViewTreeObserver viewTreeObserver =
       mPopupWindow.getContentView().getRootView().getViewTreeObserver();
   viewTreeObserver.removeOnComputeInternalInsetsListener(mInsetsComputer);
   viewTreeObserver.addOnComputeInternalInsetsListener(mInsetsComputer);
 }