public List<FeatureRequirement> featuresRequired() {
            switch (this) {
                case CLASSIC:
                    return featuresRequiredByClassic;
                case CREW:
                    return featuresRequiredByCrew;
                case MODERN:
                    return featuresRequiredByModern;
                case GRATEFUL:
                    return featuresRequiredByGrateful;
                case SINK:
                    return featuresRequiredBySink;
            }

            throw new RuntimeException("No features for this GraphData type");
        }
Loads a test graph which contains disconnected subgraphs specialized for testing purposes (e.g. a subgraph
with a self-loop).
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/LoadGraphWith.java