public TreeMap<AggregationFunctionColumnPair, AggregationSpec> getAggregationSpecs() {
    return _aggregationSpecs;
  }
@Test
  public void testUniqueAggregationSpecs() {
    TreeMap<AggregationFunctionColumnPair, AggregationSpec> expected = new TreeMap<>();
    expected.put(AggregationFunctionColumnPair.fromColumnName("count__*"), AggregationSpec.DEFAULT);
    expected.put(AggregationFunctionColumnPair.fromColumnName("sum__dimX"), AggregationSpec.DEFAULT);

    Configuration metadataProperties = createMetadata(List.of("dimX"), expected);
    StarTreeV2Metadata starTreeV2Metadata = new StarTreeV2Metadata(metadataProperties);
    TreeMap<AggregationFunctionColumnPair, AggregationSpec> actual = starTreeV2Metadata.getAggregationSpecs();
    assertEquals(expected, actual);
  }