code: function numericIndexGetter(row, index) {
      if (row == null)
          return '';
      // mimic behavior of deepValueGetter
      if (!row || index == null)
          return row;
      var value = row[index];
      if (value == null)
          return '';
      return value;
  }
docs: Returns the value at this numeric index.
  @param row array of values
  @param index numeric index
  @returns {any} or '' if invalid index