@Test
    public void shouldGetSize() {
        final TraverserSet<String> ts = traverserSetMaker.get();
        ts.add(makeTraverser("a", 1));
        ts.add(makeTraverser("a", 1));
        ts.add(makeTraverser("b1", 1));
        ts.add(makeTraverser("b2", 2));
        ts.add(makeTraverser("c", 1));

        assertEquals(4, ts.size());
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/process/traversal/traverser/util/TraverserSetImplementationTest.java