code: protected TagView getLastNormalTagView() {
          final int lastNormalTagIndex = isAppendMode ? getChildCount() - 2 : getChildCount() - 1;
          TagView lastNormalTagView = getTagAt(lastNormalTagIndex);
          return lastNormalTagView;
      }
docs: Return the last NORMAL state tag view in this group.
  
  @return the last NORMAL state tag view or null if not exists