@Test
    public void shouldBeVerifiedIllegal() {
        final String repr = traversal.getGremlinLang().getGremlin();
        try {
            ReadOnlyStrategy.instance().apply(this.traversal.asAdmin());
            fail("The strategy should have found a mutating step: " + repr);
        } catch (VerificationException ise) {
            assertThat(repr, ise.getMessage(), startsWith("The provided traversal has a mutating step and thus is not read only: "));
        }
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/verification/ReadOnlyStrategyTest.java