code: C getSizedCell(int itemIndex) {
          C cell = cellManager.getCell(itemIndex);
          double breadth = sizeTracker.breadthFor(itemIndex);
          double length = sizeTracker.lengthFor(itemIndex);
          orientation.resize(cell, breadth, length);
          return cell;
      }
docs: Returns properly sized, but not properly positioned cell for the given
  index.