public Interval locate(DataColumn column, Integer intervalIndex) {
    ColumnGroup columnGroup = column.getColumnGroup();
    if (columnGroup == null) return null;
    if (intervalIndex == null) return null;

    IntervalListLabel intervalList = new IntervalListLabel(columnGroup);
    intervalList.indexValues(column.getValues(), null);
    if (intervalIndex >= intervalList.size()) return null;
    return intervalList.get(intervalIndex);
  }
 public IntervalList build(DataColumn dataColumn) {
   ColumnGroup columnGroup = dataColumn.getColumnGroup();
   IntervalListLabel intervalList = new IntervalListLabel(columnGroup);
   List values = dataColumn.getValues();
   return intervalList.indexValues(values, null);
 }
 private void assertColumnIdAndType(DataSet result, String columnId, ColumnType columnType) {
   DataColumn amountCol = result.getColumnById(columnId);
   Assert.assertNotNull(amountCol);
   Assert.assertEquals(amountCol.getColumnType(), columnType);
 }