public void testSingleDataset() throws IOException {
    InvCatalogImpl cat = TestTDSAll.open(null);

    InvDataset ds = cat.findDatasetByID("testSingleDataset");
    assert (ds != null) : "cant find dataset 'testSingleDataset'";
    assert ds.getDataType() == FeatureType.GRID;

    ThreddsDataFactory fac = new ThreddsDataFactory();

    ThreddsDataFactory.Result dataResult = fac.openFeatureDataset(ds, null);

    assert dataResult != null;
    assert !dataResult.fatalError;
    assert dataResult.featureDataset != null;

    GridDataset gds = (GridDataset) dataResult.featureDataset;
    GridDatatype grid = gds.findGridDatatype("Z_sfc");
    assert grid != null;
    GridCoordSystem gcs = grid.getCoordinateSystem();
    assert gcs != null;
    assert null == gcs.getVerticalAxis();

    CoordinateAxis1D time = gcs.getTimeAxis1D();
    assert time != null;
    assert time.getSize() == 1;
    assert 102840.0 == time.readScalarDouble();

    dataResult.featureDataset.close();
  }