code: public final void setDivider(final int index, @StringRes final int titleId) {
          Divider divider = new Divider();
          divider.setTitle(getContext(), titleId);
          adapter.set(index, divider);
          adaptGridViewHeight();
      }
docs: Replaces the item at a specific index with a divider.
  
  @param index
  The index of the item, which should be replaced, as an {@link Integer} value
  @param titleId
  The resource id of the title of the divider, which should be added, as an {@link
  Integer} value. The resource id must correspond to a valid string resource