@Test
    public void shouldDetermineAbsentPropertiesEqual() {
        Property<?> p1 = mock(Property.class);
        Property<?> p2 = mock(Property.class);

        when(p1.isPresent()).thenReturn(false);
        when(p2.isPresent()).thenReturn(false);

        assertTrue(ElementHelper.areEqual(p1, p2));
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/structure/util/ElementHelperTest.java