if (attempt < 10) {
                    Thread.sleep(500); // First 10 attempts: 0.5 second intervals
                } else if (attempt < 30) {
                    Thread.sleep(1000); // Next 20 attempts: 1 second intervals
                } else {
                    Thread.sleep(2000); // Remaining attempts: 2 second intervals
                }
            }
        }

   * IllegalArgumentException} if passed a {@code fromKey} less than an earlier {@code fromKey}.
   * However, this method doesn't throw an exception in that situation, but instead keeps the
   * original {@code fromKey}. Similarly, this method keeps the original {@code toKey}, instead of
   * throwing an exception, if passed a {@code toKey} greater than an earlier {@code toKey}.
   */
  @Override

    override fun writeTo(sink: BufferedSink) {
      try {
        var i = 0
        while (i < contentLength()) {
          sink.write(chunk!!)
          sink.flush()
          Thread.sleep(100)
          i += chunk.size
        }
      } catch (e: IOException) {
        ioe = e
      } catch (e: InterruptedException) {
        throw RuntimeException(e)
      }
    }
  }

  private fun waitForConnectionShutdown(connection: RealConnection?) {
    if (connection!!.isHealthy(false)) {
      Thread.sleep(100L)
    }
    if (connection.isHealthy(false)) {
      Thread.sleep(2000L)
    }
    if (connection.isHealthy(false)) {
      throw TimeoutException("connection didn't shutdown within timeout")
    }
  }

  /**

      }

    /**
     * Sets the interval between HTTP/2 and web socket pings initiated by this client. Use this to
     * automatically send ping frames until either the connection fails or it is closed. This keeps
     * the connection alive and may detect connectivity failures.
     *
     * If the server does not respond to each ping with a pong within `interval`, this client will

    `HandshakeCertificates` holds the TLS certificates required for a TLS handshake. On the server
    it keeps your `HeldCertificate` and its chain. On the client it keeps the root certificates
    that are trusted to sign a server's certificate chain. `HandshakeCertificates` also works with
    mutual TLS where these roles are reversed.

      Object oldValue = ref.get();
      if (oldValue == null) {
        expectedComputations++;
      }
      ref = new WeakReference<>(cache.getUnchecked(1));
      oldValue = null;
      Thread.sleep(i);
      System.gc();
    }
    assertThat(countingLoader.getCount()).isEqualTo(expectedComputations);

    for (int i = 0; i < iterations; i++) {

      Object oldValue = ref.get();
      if (oldValue == null) {
        expectedComputations++;
      }
      ref = new WeakReference<>(cache.getUnchecked(1));
      oldValue = null;
      Thread.sleep(i);
      System.gc();
    }
    assertThat(countingLoader.getCount()).isEqualTo(expectedComputations);

    for (int i = 0; i < iterations; i++) {

     * is the only one in use, but if we encounter nested concatenations, we start a deque of
     * meta-iterators rather than letting the nesting get arbitrarily deep.  This keeps each
     * operation O(1).
     */

    private @Nullable Iterator<? extends Iterator<? extends T>> topMetaIterator;

    // Only becomes nonnull if we encounter nested concatenations.

    assertThat(connection.isHealthy(System.nanoTime())).isTrue()

    // But if the ping doesn't arrive, the connection goes unhealthy.
    Thread.sleep(TimeUnit.NANOSECONDS.toMillis(Http2Connection.DEGRADED_PONG_TIMEOUT_NS.toLong()))
    assertThat(connection.isHealthy(System.nanoTime())).isFalse()

    // When a pong does arrive, the connection becomes healthy again.