this.exec = newCachedThreadPool();
    this.future = checkNotNull(future);
    this.latch = new CountDownLatch(1);
  }

  public void setUp() {
    future.addListener(latch::countDown, exec);

    assertEquals(1, latch.getCount());
    assertFalse(future.isDone());
    assertFalse(future.isCancelled());
  }

  public void tearDown() {
    exec.shutdown();
  }

    return new ListenerCallQueue.Event<Object>() {
      @Override
      public void call(Object listener) {
        latch.countDown();
      }

      @Override
      public String toString() {
        return "countDown";
      }
    };
  }

    return new ListenerCallQueue.Event<Object>() {
      @Override
      public void call(Object listener) {
        latch.countDown();
      }

      @Override
      public String toString() {
        return "countDown";
      }
    };
  }

 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * {@snippet :
 * final CountDownLatch latch = new CountDownLatch(1);
 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null; // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);
 * }
 *
 * <p>Here's an example that uses a user-defined finalization predicate:
 *
 * {@snippet :

 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * {@snippet :
 * final CountDownLatch latch = new CountDownLatch(1);
 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null; // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);
 * }
 *
 * <p>Here's an example that uses a user-defined finalization predicate:
 *
 * {@snippet :

          response: Response,
        ) {
          bodies.add(response.body.string())
          latch.countDown()
        }

        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          errors.add(e)
          latch.countDown()
        }
      }
    client.newCall(Request.Builder().url(server.url("/")).build()).enqueue(
      callback,

          e: IOException,
        ) {
          exceptionRef.set(e)
          latch.countDown()
        }

        @Throws(IOException::class)
        override fun onResponse(
          call: Call,
          response: Response,
        ) {
          response.close()
          latch.countDown()
        }
      },
    )
    latch.await()
    assertThat(call.isCanceled()).isTrue()

                            Thread.currentThread().interrupt();
                        } finally {
                            endLatch.countDown();
                        }
                    });
                }

                startLatch.countDown(); // Start all threads simultaneously
                assertTrue("Concurrent registration timed out", endLatch.await(10, TimeUnit.SECONDS));

        cache.getUnchecked(getKey);
        getFinishedSignal.countDown();
      }
    }.start();
    new Thread() {
      @Override
      public void run() {
        cache.refresh(refreshKey);
        getFinishedSignal.countDown();
      }
    }.start();

    // let computation complete
    letGetFinishSignal.countDown();
    getFinishedSignal.await();
    checkNothingLogged();

          reason: String,
        ) {
          webSocket.close(1000, null)
          latch.countDown()
        }

        override fun onFailure(
          webSocket: WebSocket,
          t: Throwable,
          response: Response?,
        ) {
          t.printStackTrace(System.out)
          latch.countDown()
        }
      },
    )