A finalAccum = scheme.result(collector, inputs);
      if (collector.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)) {
        @SuppressWarnings("unchecked") // `R` and `A` match for an `IDENTITY_FINISH`
        R result = (R) finalAccum;
        assertEquivalent(expectedResult, result);
      }
      assertEquivalent(expectedResult, collector.finisher().apply(finalAccum));

   * to calling it exactly once.
   *
   * @since 10.0 (present in 1.0 as {@code run})
   */
  public void execute() {
    // Lock while we update our state so the add method above will finish adding any listeners
    // before we start to run them.
    RunnableExecutorPair list;
    synchronized (this) {
      if (executed) {
        return;
      }
      executed = true;

  private static final class Failure {
    static final Failure FALLBACK_INSTANCE =
        new Failure(
            new Throwable("Failure occurred while trying to finish a future.") {
              @Override
              public synchronized Throwable fillInStackTrace() {
                return this; // no stack trace
              }
            });
    final Throwable exception;

            inputs.assertHasImmediateFailure(iFuture, jFuture, e);
          } catch (TimeoutException e) {
            inputs.assertHasDelayed(iFuture, jFuture, e);
          }

          // Finish the two futures in the currently specified order:
          inputs.allFutures.get(iBeforeJ ? i : j).finisher.run();
          inputs.allFutures.get(iBeforeJ ? j : i).finisher.run();

   *
   * @param executor the executor to modify to make sure it exits when the application is finished
   * @param terminationTimeout how long to wait for the executor to finish before terminating the
   *     JVM
   * @param timeUnit unit of time for the time parameter
   * @return an unmodifiable version of the input which will not hang the JVM
   */
  @J2ktIncompatible

            inputs.assertHasImmediateFailure(iFuture, jFuture, e);
          } catch (TimeoutException e) {
            inputs.assertHasDelayed(iFuture, jFuture, e);
          }

          // Finish the two futures in the currently specified order:
          inputs.allFutures.get(iBeforeJ ? i : j).finisher.run();
          inputs.allFutures.get(iBeforeJ ? j : i).finisher.run();

      Executor executor) {
    return AbstractCatchingFuture.create(input, exceptionType, fallback, executor);
  }

  /**
   * Returns a future that delegates to another but will finish early (via a {@link
   * TimeoutException} wrapped in an {@link ExecutionException}) if the specified duration expires.
   *
   * <p>The delegate future is interrupted and cancelled if it times out.
   *