* @return the key associated with the request
     * @throws IOException if an I/O error occurs
     */
    protected <T extends Response> long doSend(final Request request, final T response, final Set<RequestParam> params, final long timeout)
            throws IOException {
        final long firstKey = prepareRequests(request, response, params, timeout);
        doSend(request);
        return firstKey;
    }

    /**

    }
  }

  /** A holder of counters for calls to hashCode, equals, and compareTo. */
  private static final class CallsCounter {
    long hashCode;
    long equals;
    long compareTo;

    long total() {
      return hashCode + equals + compareTo;
    }

    void zero() {
      hashCode = 0;
      equals = 0;
      compareTo = 0;
    }
  }

   *
   * <p>Instead of throwing {@link ArithmeticException}, this method silently saturates to either
   * {@link Long#MAX_VALUE} or {@link Long#MIN_VALUE}. This behavior can be useful when decomposing
   * a duration in order to call a legacy API which requires a {@code long, TimeUnit} pair.
   */
  static long toNanosSaturated(Duration duration) {
    // Using a try/catch seems lazy, but the catch block will rarely get invoked (except for

    return SECONDS.toMicros(1L) / stableIntervalMicros;
  }

  @Override
  final long queryEarliestAvailable(long nowMicros) {
    return nextFreeTicketMicros;
  }

  @Override
  final long reserveEarliestAvailable(int requiredPermits, long nowMicros) {
    resync(nowMicros);
    long returnValue = nextFreeTicketMicros;
    double storedPermitsToSpend = min(requiredPermits, this.storedPermits);

    @Override
    public final long getLastAccessTime() {
        return this.lastAccessTime;
    }

    /**
     * @return the lastWriteTime
     */
    @Override
    public final long getLastWriteTime() {
        return this.lastWriteTime;
    }

    /**
     * Gets the allocation size.
     *
     * @return the allocationSize
     */
    public final long getAllocationSize() {

    /** Flag indicating whether a previous page exists. */
    protected boolean existPrevPage;

    /** Starting record number for the current page. */
    protected long currentStartRecordNumber;

    /** Ending record number for the current page. */
    protected long currentEndRecordNumber;

    /** List of page numbers for pagination navigation. */
    protected List<String> pageNumberList;

      Runnable command, long initialDelay, long period, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  ListenableScheduledFuture<?> scheduleWithFixedDelay(
      Runnable command, long initialDelay, long delay, TimeUnit unit);

 */
final class LongAdder extends Striped64 implements Serializable, LongAddable {
  @GwtIncompatible @J2ktIncompatible   private static final long serialVersionUID = 7249069246863182397L;

  /** Version of plus for use in retryUpdate */
  @Override
  final long fn(long v, long x) {
    return v + x;
  }

  /** Creates a new adder with initial sum of zero. */
  public LongAdder() {}

  /**
   * Adds the given value.

    @Test
    public void test_waitForNext_withPositiveInterval() throws InterruptedException {
        configHelper.setReloadInterval(20L);

        long startTime = System.currentTimeMillis();
        configHelper.waitForNext();
        long endTime = System.currentTimeMillis();

        long elapsed = endTime - startTime;
        assertTrue("Expected at least 15ms sleep, got " + elapsed + "ms", elapsed >= 15);

            final long indexTime) {
        final double cpuLoad;
        if (ManagementFactory.getOperatingSystemMXBean() instanceof final com.sun.management.OperatingSystemMXBean operatingSystemMXBean) {
            cpuLoad = operatingSystemMXBean.getProcessCpuLoad();
        } else {
            cpuLoad = -1;
        }
        final long maxMemory = Runtime.getRuntime().maxMemory();