class ShapeInMemLayer extends FeatureSourceRetriever implements VectorLayer {

	@Override
	public Object create(Object feature) throws LayerException {
		String id = featureModel.getId(feature);
		if (id != null && !features.containsKey(id)) {
			SimpleFeature realFeature = asFeature(feature);
			features.put(id, realFeature);
			return realFeature;
		}
		return null;
	}

}