@Override
    protected List<Traversal> getTraversals() {
        return Arrays.asList(
                __.count().is(0),
                __.count().is(P.gt(0)),
                __.count().is(1)
        );
    }
@author Daniel Kuppitz (http://gremlin.guru)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/step/filter/IsStepTest.java