@Override
    protected List<Traversal> getTraversals() {
        return Arrays.asList(
                __.flatMap((Traverser<Vertex> t) -> t.get().edges(Direction.OUT, "knows")),
                __.flatMap((Traverser<Vertex> t) -> t.get().edges(Direction.OUT, "created"))
        );
    }
@author Daniel Kuppitz (http://gremlin.guru)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/LambdaFlatMapStepTest.java