DataLayer headerLayer = new DataLayer(emptyOneCellHeaderDataProvider, 50, 20);

//just adding the 	Configuration does not work. Try overriding and using labels: add GridRegion.ROW_HEADER
ColumnLabelAccumulator overrideLabelAccumulator = new ColumnLabelAccumulator(){
	@Override
	public void accumulateConfigLabels(LabelStack configLabels,
			int columnPosition, int rowPosition) {
		super.accumulateConfigLabels(configLabels, columnPosition, rowPosition);
		configLabels.addLabel(GridRegion.ROW_HEADER); //add GridRegion.ROW_HEADER, so that DefaultRowHeaderLayerConfiguration starts to work
	}
};
headerLayer.setConfigLabelAccumulator(overrideLabelAccumulator);

//reuse the default configurations. This makes the row header look like a header.
DefaultRowHeaderLayerConfiguration configuration = new DefaultRowHeaderLayerConfiguration();

//add to layer
headerLayer.addConfiguration(configuration);