@Test
    public void shouldValidatePropertyAndNotAllowHiddenKey() {
        final String key = Graph.Hidden.hide("key");
        try {
            ElementHelper.validateProperty(key, "test");
            fail("Should fail as property key cannot be hidden");
        } catch (IllegalArgumentException iae) {
            assertEquals(Property.Exceptions.propertyKeyCanNotBeAHiddenKey(key).getMessage(), iae.getMessage());
        }
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/structure/util/ElementHelperTest.java