@Test
    public void shouldIdentifyThatKeyExistsWithNullsMixedIn() {
        assertThat(ElementHelper.keyExists("k", null, null, "k"), is(true));
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/structure/util/ElementHelperTest.java