ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();
    assertFalse(executor.isShutdown());
    assertFalse(executor.isTerminated());
    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertTrue(executor.isTerminated());
  }

  public void testNoOpScheduledExecutorInvokeAll() throws ExecutionException, InterruptedException {

    ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();
    assertFalse(executor.isShutdown());
    assertFalse(executor.isTerminated());
    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertTrue(executor.isTerminated());
  }

  public void testNoOpScheduledExecutorInvokeAll() throws ExecutionException, InterruptedException {

 * with the abstract {@link #execute execute(Runnable)} method.
 *
 * <p>In addition to {@link #execute}, subclasses must implement all methods related to shutdown and
 * termination.
 *
 * @author Chris Povirk
 * @since 14.0
 */
@CheckReturnValue
@GwtIncompatible
public abstract class AbstractListeningExecutorService extends AbstractExecutorService

            listenerLatch.countDown();
          }
        },
        directExecutor());
  }

  @Override
  protected void tearDown() throws Exception {
    if (exec != null) {
      exec.shutdown();
    }

    super.tearDown();
  }

  public void testListenerDoesNotRunUntilTaskCompletes() throws Exception {

    // Test default state of not started.
    assertEquals(1, listenerLatch.getCount());

          .addAllowedQuicHost("www.google.com")
          .build(),
      ).addQuicHint("google.com", 443, 443)
      .addQuicHint("www.google.com", 443, 443)
      .build()

  @After
  fun tearDown() {
    engine.shutdown()
    cacheDir.deleteRecursively()
  }

  @Test
  fun get() {
    val executor = Executors.newCachedThreadPool()

    val completableFuture = execute(engine, executor, "https://google.com/robots.txt")

                logger.debug("Shutting down thread executor.");
            }
            executor.shutdown();
            executor.awaitTermination(executorTerminationTimeout, TimeUnit.SECONDS);
        } catch (final InterruptedException e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Executor shutdown interrupted", e);
            }
        } finally {
            executor.shutdownNow();
        }

                    latch.countDown();
                }
            });
        }

        assertTrue(latch.await(10, TimeUnit.SECONDS), "Concurrent operations should complete");
        executor.shutdown();

        // Circuit breaker should have handled concurrent operations
        assertTrue(successCount.get() > 0, "Should have some successful operations");

      }
      barrier.await(); // release the threads!
      barrier.await(); // wait for them all to complete
      assertEquals(1, task.get().intValue());
      assertEquals(1, counter.get());
    }
    executor.shutdown();
  }

  @J2ktIncompatible
  @GwtIncompatible // blocking wait
  public void testToString() throws Exception {
    CountDownLatch enterLatch = new CountDownLatch(1);

      executor.execute(() -> {
        try {
          drainQueue();
        } catch (Throwable e) {
          e.printStackTrace();
        }
      });
    }
    executor.shutdown();
  }

  private void drainQueue() throws Exception {
    for (HttpUrl url; (url = queue.take()) != null; ) {
      if (!fetchedUrls.add(url)) {
        continue;
      }

## Version 3.4.2

_2016-11-03_

 *  Fix: Recover gracefully when an HTTP/2 connection is shutdown. We had a
    bug where shutdown HTTP/2 connections were considered usable. This caused
    infinite loops when calls attempted to recover.


## Version 3.4.1

_2016-07-10_

 *  **Fix a major bug in encoding HTTP headers.** In 3.4.0 and 3.4.0-RC1 OkHttp