/**
 * A future that, if it fails, may <i>optionally</i> provide access to the cause of the failure.
 *
 * <p>This class is used only for micro-optimization. Standard {@code Future} utilities benefit from
 * this optimization, so there is no need to specialize methods to return or accept this type
 * instead of {@code ListenableFuture}.
 *
 * <p>This class is GWT-compatible.
 *

 * inputs' {@link Comparable#compareTo compareTo} and {@link Comparator#compare compare} methods as
 * soon as one of them returns a nonzero result. This optimization is typically important only in
 * the presence of expensive {@code compareTo} and {@code compare} implementations.
 *
 * <p>See the Guava User Guide article on <a href=

       * need access to the futures again, so we can just pass `null`.
       *
       * TODO(b/112550045): Allocating a single, cheaper listener is (I think) only an optimization.
       * If we make some other optimizations, this one will no longer be necessary. The optimization
       * could actually hurt in some cases, as it forces us to keep all inputs in memory until the
       * final input completes.
       */

    }
    return null;
  }

  @Override
  protected void afterDone() {
    maybePropagateCancellationTo(delegateRef);

    Future<?> localTimer = timer;
    // Try to cancel the timer as an optimization.
    // timer may be null if this call to run was by the timer task since there is no happens-before
    // edge between the assignment to timer and an execution of the timer task.
    if (localTimer != null) {

 * inputs' {@link Comparable#compareTo compareTo} and {@link Comparator#compare compare} methods as
 * soon as one of them returns a nonzero result. This optimization is typically important only in
 * the presence of expensive {@code compareTo} and {@code compare} implementations.
 *
 * <p>See the Guava User Guide article on <a href=

       * crashes on Android when running in 32-bit mode. For maximum safety, we shouldn't use
       * Unsafe.getLong() at all, but the performance benefit on x86_64 is too great to ignore, so
       * as a compromise, we enable the optimization only on platforms that we specifically know to
       * work.
       *
       * In the future, the use of Unsafe.getLong() should be replaced by ByteBuffer.getLong(),

    }
  }

  /**
   * Exactly like signalNextWaiter, but caller guarantees that guardToSkip need not be considered,
   * because caller has previously checked that guardToSkip.isSatisfied() returned false. An
   * optimization for the case that guardToSkip.isSatisfied() may be expensive.
   *
   * <p>We decided against using this method, since in practice, isSatisfied() is likely to be very

      return checkNotNull(otherConverter, "otherConverter");
    }

    /*
     * We *could* override convertAll() to return its input, but it's a rather pointless
     * optimization and opened up a weird type-safety problem.
     */

    @Override
    public String toString() {
      return "Converter.identity()";
    }

    private Object readResolve() {

    // The alternative (x + y) / 2 fails for large values.
    // The alternative (x + y) >>> 1 fails for negative values.
    return (x & y) + ((x ^ y) >> 1);
  }

  /*
   * This bitmask is used as an optimization for cheaply testing for divisibility by 2, 3, or 5.
   * Each bit is set to 1 for all remainders that indicate divisibility by 2, 3, or 5, so

    }
  }

  /**
   * Tests that nHMWES makes hash maps large enough that adding the expected number of elements
   * won't cause a rehash.
   *
   * <p>As of jdk7u40, HashMap has an empty-map optimization. The argument to new HashMap(int) is
   * noted, but the initial table is a zero-length array.
   *
   * <p>This test may fail miserably on non-OpenJDK environments...
   */
  @J2ktIncompatible