*/
FeatureDefn feature = layer.GetLayerDefn();
gdal.ContourGenerate(band, contourInterval, offset, fixedLevelsDouble,
(ignoreNodata ? 1 : 0), sourceNodata, layer, feature.GetFieldIndex("ID"),
(attributName != null ? feature.GetFieldIndex(attributName) : -1),
progressCallback);
dataSource.delete();
dataset.delete();