code: public final void addItem(final int id, @NonNull final CharSequence title,
                                @Nullable final Drawable icon) {
          Item item = new Item(id, title);
          item.setIcon(icon);
          adapter.add(item);
          adaptGridViewHeight();
      }
docs: Adds a new item to the bottom sheet.
  
  @param id
  The id of the item, which should be added, as an {@link Integer} value. The id must
  be at least 0
  @param title
  The title of the item, which should be added, as an instance of the type {@link
  CharSequence}. The title may neither be null, nor empty
  @param icon
  The icon of the item, which should be added, as an instance of the class {@link
  Drawable}, or null, if no item should be used