@Override
    protected List<Traversal> getTraversals() {
        return Arrays.asList(
                __.elementMap(),
                __.elementMap("name"),
                __.elementMap("age"),
                __.elementMap("name", "age")
        );
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/map/ElementMapStepTest.java