@Test
    public void shouldHandleHasIdAmbiguousNull() throws Exception {
        final GraphTraversalSource g = traversal().withEmbedded(EmptyGraph.instance());
        final Bindings bindings = new SimpleBindings();
        bindings.put("g", g);
        ambiguousNullEngine.eval("g.V().hasId(null)", bindings);
        ambiguousNullEngine.eval("g.V().hasId(P.eq(1), null)", bindings);
    }
Test for TINKERPOP-2394 Unable to use __ class of a custom DSL when passing a script even if this class is imported
gremlin-groovy/src/test/java/org/apache/tinkerpop/gremlin/groovy/jsr223/GremlinGroovyScriptEngineTest.java