code: @Override
      public List<BaseCell> getItems(@NonNull Card card) {
          if (card.style != null && !TextUtils.isEmpty(card.style.forLabel)) {
              String forId = card.style.forLabel;
              if (mIdCardCache.containsKey(forId)) {
                  Card forCard = mIdCardCache.get(forId);
                  // if the "forLabel" card is empty, this card also should be empty
                  if (forCard.mCells.size() == 0) {
                      if (TextUtils.isEmpty(forCard.load)) {
                          return null;
                      } else {
                          return Collections.emptyList();
                      }
                  }
              }
          }
  
          if (TextUtils.isEmpty(card.load) && card.mCells.isEmpty()) {
              return null;
          }
          return new LinkedList<>(card.mCells);
      }
docs: Get correspond items for card
  
  @param card the card look items for
  @return cells of this card