@Test
lic void testTo()
{

    try
    {
        Set<Vertex<String>> t = connect.to(b);
        assertTrue(t.contains(a));
        assertTrue(t.contains(c));
        t = disConnect.to(b);
        assertTrue(t.size() == 0);
    }
    catch (DirectedGraphException ex)
    {
        edu.ku.brc.af.core.UsageTracker.incrHandledUsageCount();
        edu.ku.brc.exceptions.ExceptionTracker.getInstance().capture(DirectedGraphTest.class, ex);
        //what?
    }
}