*
   * <pre>{@code
   * awaitDone(new FinalizationPredicate() {
   *   public boolean isDone() {
   *     return ref.get() == null;
   *   }
   * });
   * }</pre>
   *
   * @throws RuntimeException if timed out or interrupted while waiting
   */
  public static void awaitClear(WeakReference<?> ref) {
    awaitDone(
        new FinalizationPredicate() {
          @Override

        new Object() {
          @Override
          protected void finalize() {
            future.set(null);
          }
        };
    x = null; // Hint to the JIT that x is unreachable
    GcFinalization.awaitDone(future);
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());
  }

  public void testAwaitDone_Future_Cancel() {
    final SettableFuture<@Nullable Void> future = SettableFuture.create();

        new Object() {
          @Override
          protected void finalize() {
            future.set(null);
          }
        };
    x = null; // Hint to the JIT that x is unreachable
    GcFinalization.awaitDone(future);
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());
  }

  public void testAwaitDone_Future_Cancel() {
    final SettableFuture<@Nullable Void> future = SettableFuture.create();

   *
   * <pre>{@code
   * awaitDone(new FinalizationPredicate() {
   *   public boolean isDone() {
   *     return ref.get() == null;
   *   }
   * });
   * }</pre>
   *
   * @throws RuntimeException if timed out or interrupted while waiting
   */
  public static void awaitClear(WeakReference<?> ref) {
    awaitDone(
        new FinalizationPredicate() {
          @Override

    assertTrue(file.exists());
    out.close();

    // Make sure that finalize deletes the file
    out = null;

    // times out and throws RuntimeException on failure
    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override
          public boolean isDone() {
            return !file.exists();
          }
        });
  }

    assertTrue(file.exists());
    out.close();

    // Make sure that finalize deletes the file
    out = null;

    // times out and throws RuntimeException on failure
    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override
          public boolean isDone() {
            return !file.exists();
          }
        });
  }

    frq = null;
  }


  public void testFinalizeReferentCalled() {
    final MockReference reference = new MockReference(frq = new FinalizableReferenceQueue());

    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          @Override
          public boolean isDone() {
            return reference.finalizeReferentCalled;
          }
        });
  }

    frq = null;
  }


  public void testFinalizeReferentCalled() {
    final MockReference reference = new MockReference(frq = new FinalizableReferenceQueue());

    GcFinalization.awaitDone(
        new GcFinalization.FinalizationPredicate() {
          public boolean isDone() {
            return reference.finalizeReferentCalled;
          }
        });
  }

    }
  }

  /** For testing: sends a ping and waits for a pong. */
  @Throws(InterruptedException::class)
  fun writePingAndAwaitPong() {
    writePing()
    awaitPong()
  }

  /** For testing: sends a ping to be awaited with [awaitPong]. */
  @Throws(InterruptedException::class)
  fun writePing() {
    this.withLock {
      awaitPingsSent++
    }

    // 0x4f 0x4b 0x6f 0x6b is "OKok".

        throw ConnectionShutdownException()
      }
    }
    connection.writePing()
    connection.shutdown(ErrorCode.PROTOCOL_ERROR)
    assertThat(connection.openStreamCount()).isEqualTo(1)
    connection.awaitPong() // Prevent the peer from exiting prematurely.

    // Verify the peer received what was expected.
    val synStream1 = peer.takeFrame()
    assertThat(synStream1.type).isEqualTo(Http2.TYPE_HEADERS)