}

    Object readResolve() {
      if (cellValues.length == 0) {
        return of();
      }
      if (cellValues.length == 1) {
        return of(rowKeys[0], columnKeys[0], cellValues[0]);
      }
      ImmutableList.Builder<Cell<Object, Object, Object>> cellListBuilder =
          new ImmutableList.Builder<>(cellValues.length);
      for (int i = 0; i < cellValues.length; i++) {
        cellListBuilder.add(