@VisibleForTesting @CalledByNativeUnchecked("BookmarkNode") public void addChild(BookmarkNode child){
  mChildren.add(child);
}

@ VisibleForTesting @ CalledByNativeUnchecked ( "BookmarkNode" ) public void addChild ( BookmarkNode child ) { mChildren . add ( child ) ; }
adds a child to this node . < p > used solely by the native code .
