docs: @Override
    public void add(MtasDataItem<T1, T2> newItem) throws IOException {
      if (newItem instanceof MtasDataItemFull) {
        MtasDataItemFull<T1, T2> newTypedItem = (MtasDataItemFull<T1, T2>) newItem;
        T1[] tmpValue = operations
            .createVector1(fullValues.length + newTypedItem.fullValues.length);
        System.arraycopy(fullValues, 0, tmpValue, 0, fullValues.length);
        System.arraycopy(newTypedItem.fullValues, 0, tmpValue, fullValues.length,
            newTypedItem.fullValues.length);
        fullValues = tmpValue;
        recomputeComparableSortValue = true;
      } else {
        throw new IOException("can only add MtasDataItemFull");
      }
    }