* ClosingFuture)} to start this combination.
   *
   * @param <V1> the type returned by the first future
   * @param <V2> the type returned by the second future
   * @param <V3> the type returned by the third future
   */
  public static final class Combiner3<
          V1 extends @Nullable Object, V2 extends @Nullable Object, V3 extends @Nullable Object>
      extends Combiner {
    /**

  private abstract static class First<T> {}

  private abstract static class Second<D> extends First<D> {}

  private abstract static class Third<T, D> extends Second<T> {}

  private abstract static class Fourth<T, D> extends Third<D, T> {}

  private static class ConcreteIntegerString extends Fourth<Integer, String> {}

  private static class ConcreteStringInteger extends Fourth<String, Integer> {}

    assertEquals("true", result.get("first"));
    assertEquals("null", result.get("second"));
    assertEquals(2, result.size());

    // Now test values loaded from a stream.
    String props = "test\n second = 2\n Third item :   a short  phrase   ";

    testProp.load(new StringReader(props));

    result = Maps.fromProperties(testProp);
    assertEquals(4, result.size());
    assertEquals("true", result.get("first"));

    CountDownLatch secondSignal = new CountDownLatch(1);
    // tells the main thread when the second get has started
    CountDownLatch thirdSignal = new CountDownLatch(1);
    // tells the main thread when the third get has started
    CountDownLatch fourthSignal = new CountDownLatch(1);
    // tells the test when all gets have returned
    CountDownLatch doneSignal = new CountDownLatch(count);

    CountDownLatch secondSignal = new CountDownLatch(1);
    // tells the main thread when the second get has started
    CountDownLatch thirdSignal = new CountDownLatch(1);
    // tells the main thread when the third get has started
    CountDownLatch fourthSignal = new CountDownLatch(1);
    // tells the test when all gets have returned
    CountDownLatch doneSignal = new CountDownLatch(count);

    assertThat(server.takeRequest().exchangeIndex).isEqualTo(1) // Pooled connection.
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(0) // New connection.

    // Third call reuses the second connection.
    val response3 = client.newCall(request).execute()
    assertThat(response3.body.string()).isEqualTo("def")
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(1) // New connection.

kubectl get thirdpartyresource --all-namespaces -o yaml > tprs.yaml
kubectl delete -f tprs.yaml

After upgrading to 1.3.0, re-register the third party resource objects at the root scope (using a 1.3 server and client):

kubectl create -f tprs.yaml

#### kubectl

    assertEquals("true", result.get("first"));
    assertEquals("null", result.get("second"));
    assertEquals(2, result.size());

    // Now test values loaded from a stream.
    String props = "test\n second = 2\n Third item :   a short  phrase   ";

    testProp.load(new StringReader(props));

    result = Maps.fromProperties(testProp);
    assertEquals(4, result.size());
    assertEquals("true", result.get("first"));