@Override
            public void vertexRemoved(final Vertex element) {
                assertEquals(v, element);
                assertEquals(id, element.id());
                assertEquals(label, element.label());
                triggered.set(true);
            }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/decoration/EventStrategyProcessTest.java