@Test
    public void shouldMakeImmutable() {
        final TraversalExplanation explanation = __.V().out().out().explain();
        final ImmutableExplanation immutable = explanation.asImmutable();
        assertEquals(explanation.prettyPrint(), immutable.prettyPrint());
        assertEquals(explanation.toString(), immutable.toString());
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/util/TraversalExplanationTest.java