*/
  abstract double coolDownIntervalMicros();

  /** Updates {@code storedPermits} and {@code nextFreeTicketMicros} based on the current time. */
  void resync(long nowMicros) {
    // if nextFreeTicket is in the past, resync to now
    if (nowMicros > nextFreeTicketMicros) {
      double newPermits = (nowMicros - nextFreeTicketMicros) / coolDownIntervalMicros();

            AbstractFuture<String> future = setFutureFuture.get();
            setFutureSetSuccess.set(currentFuture.get().setFuture(future));
            setFutureCompletionSuccess.set(future.set("hello-async-world"));
            awaitUnchecked(barrier);
          }
        };
    final Set<Object> finalResults = Collections.synchronizedSet(Sets.newIdentityHashSet());
    Runnable collectResultsRunnable =

   * as implementation details.
   *
   * <p>Since the bimap is immutable, ImmutableBiMap doesn't require special logic for keeping the
   * bimap and its inverse in sync during serialization, the way AbstractBiMap does.
   */
  @J2ktIncompatible // serialization
  private static class SerializedForm<K, V> extends ImmutableMap.SerializedForm<K, V> {

            AbstractFuture<String> future = setFutureFuture.get();
            setFutureSetSuccess.set(currentFuture.get().setFuture(future));
            setFutureCompletionSuccess.set(future.set("hello-async-world"));
            awaitUnchecked(barrier);
          }
        };
    final Set<Object> finalResults = Collections.synchronizedSet(Sets.newIdentityHashSet());
    Runnable collectResultsRunnable =