/**
   * Retrun the value at row #<code>row</code> as a char.
   *
   * @param row the row number
   * @return the item at row as a char, if no such item exists return a value signifying the
   *     position is empty, as defined by SparseCharColumn.
   */
  public char getChar(int row) {
    Object obj = elements.get(row);
    if (obj != null) {
      return SparseCharColumn.toChar(obj);
    }

    return SparseDefaultValues.getDefaultChar();
  }