/**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessage the exception message to use if the check fails; will be converted to a
   *     string using {@link String#valueOf(Object)}
   * @throws IllegalArgumentException if {@code expression} is false
   */

    }
    // The future has already been set to something. If it is cancellation we should cancel the
    // incoming future.
    if (localValue instanceof Cancellation) {
      // we don't care if it fails, this is best-effort.
      future.cancel(((Cancellation) localValue).wasInterrupted);
    }
    return false;
  }

  /**

  }

  /**
   * Returns a new {@code Future} whose result is asynchronously derived from the result of the
   * given {@code Future}. If the given {@code Future} fails, the returned {@code Future} fails with
   * the same exception (and the function is not invoked).
   *
   * <p>More precisely, the returned {@code Future} takes its result from a {@code Future} produced

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessage the exception message to use if the check fails; will be converted to a
   *     string using {@link String#valueOf(Object)}
   * @throws IllegalArgumentException if {@code expression} is false
   */

   *   ClassLoader that is sometimes used as a system classloader. That's a problem because
   *   method-reference linking tries to look up the system classloader, and it fails because there
   *   isn't one yet.
   *
   * - lambda: Outside Google, we got a report of a similar problem in
   *   https://github.com/google/guava/issues/6565
   */
  @SuppressWarnings("AnonymousToLambda")