// we should get an ExecutionException; if we call getUnchecked(), we should get an
      // UncheckedExecutionException.
      int mod = i % 3;
      if (mod == 0 || mod == 2) {
        assertThat(result.get(i)).isInstanceOf(ExecutionException.class);
        assertThat((ExecutionException) result.get(i)).hasCauseThat().isSameInstanceAs(e);
      } else {

     * cancelled.
     *
     * <p>If the combiner throws an {@code ExecutionException}, the cause of the thrown {@code
     * ExecutionException} will be extracted and returned as the cause of the new {@code
     * ExecutionException} that gets thrown by the returned combined future.
     *
     * <p>Canceling this future will attempt to cancel all the component futures.

  }

  /**
   * Marks the given step final, waits for it to be finished, and returns the value.
   *
   * @throws ExecutionException if the step failed
   * @throws CancellationException if the step was cancelled
   */
  abstract <T> T getFinalValue(ClosingFuture<T> closingFuture) throws ExecutionException;

  /** Marks the given step final, cancels it, and waits for the cancellation to happen. */

import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;