@Test
  public void testRetrieveTransmissionNode() {

    System.out.println("- testRetrieveTransmissionNode -");

    System.out.println("Retrieve transmission for host1 from most recent transission nodes list");
    TransmissionNode tn1 = tt.retrieveTransmissionNode(host1);
    System.out.println(tn1.toString());

    // fail("Not yet implemented");
  }
  @Test
  public void testIsRoot() {

    System.out.println("- testIsRoot -");

    System.out.println("test the root node - should be a root");
    TransmissionNode rootNode = tt.rootNode;
    System.out.println(rootNode.toString());
    assertTrue(tt.isRoot(rootNode));
    assertTrue(tt.isRoot(tt.getRootTransmissionNode()));
    assertTrue(tt.isRoot((TransmissionNode) tt.nodes.get(0)));

    System.out.println("test nodes corresponding to hosts 1 & 2 - should not be a root");
    assertTrue(!tt.isRoot(tt.retrieveTransmissionNode(host1)));
    assertTrue(!tt.isRoot(tt.retrieveTransmissionNode(host2)));
  }