}

	compactors[key].refs++

	return func() {
		compactorsMu.Lock()
		defer compactorsMu.Unlock()

		compactor := compactors[key]
		compactor.refs--
		if compactor.refs == 0 {
			compactor.cancel()
			compactor.client.Close()
			delete(compactors, key)
		}
	}, nil
}

	if err != etcdrpc.ErrCompacted {
		t.Errorf("Expecting ErrCompacted, but get=%v err=%v", obj, err)
	}
}

// TestCompactConflict tests that two compactors (Let's use C1, C2) are trying to compact etcd cluster with the same
// logical time.
// - C1 compacts first. It will succeed.
// - C2 compacts after. It will fail. But it will get latest logical time, which should be larger by one.
func TestCompactConflict(t *testing.T) {

 * the JDK.
 *
 * @since 21.0
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Comparators {
  private Comparators() {}

  /**
   * Returns a new comparator which sorts iterables by comparing corresponding elements pairwise
   * until a nonzero result is found; imposes "dictionary order." If the end of one iterable is

 * the JDK.
 *
 * @since 21.0
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Comparators {
  private Comparators() {}

  /**
   * Returns a new comparator which sorts iterables by comparing corresponding elements pairwise
   * until a nonzero result is found; imposes "dictionary order." If the end of one iterable is

	// Technical details/insights:
	//
	// The protocol here is lease based. If one compactor CAS successfully, the others would know it when they fail in
	// CAS later and would try again in 5 minutes. If an APIServer crashed, another one would "take over" the lease.
	//
	// For example, in the following diagram, we have a compactor C1 doing compaction in t1, t2. Another compactor C2

    assertTrue(Comparators.isInOrder(asList(0, 0, 3, 3), Ordering.natural()));
    assertTrue(Comparators.isInOrder(asList(0, 3), Ordering.natural()));
    assertTrue(Comparators.isInOrder(Collections.singleton(1), Ordering.natural()));
    assertTrue(Comparators.isInOrder(Collections.<Integer>emptyList(), Ordering.natural()));
  }

  public void testIsInStrictOrder() {

    this.comparators = (Comparator<? super T>[]) new Comparator<?>[] {primary, secondary};
  }

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Iterable<? extends Comparator<? super T>> comparators) {
    this.comparators =
        Iterables.toArray(comparators, (Comparator<? super T>[]) new Comparator<?>[0]);
  }

  @Override

    this.comparators = (Comparator<? super T>[]) new Comparator<?>[] {primary, secondary};
  }

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Iterable<? extends Comparator<? super T>> comparators) {
    this.comparators =
        Iterables.toArray(comparators, (Comparator<? super T>[]) new Comparator<?>[0]);
  }

  @Override

   * to {@code reduce}).
   *
   * @param comparators the comparators to try in order
   */
  @GwtCompatible(serializable = true)
  public static <T extends @Nullable Object> Ordering<T> compound(
      Iterable<? extends Comparator<? super T>> comparators) {
    return new CompoundOrdering<>(comparators);
  }

  /**

/**
 * Implementation of {@code Multimap} whose keys and values are ordered by their natural ordering or
 * by supplied comparators. In all cases, this implementation uses {@link Comparable#compareTo} or
 * {@link Comparator#compare} instead of {@link Object#equals} to determine equivalence of
 * instances.
 *
 * <p><b>Warning:</b> The comparators or comparables used must be <i>consistent with equals</i> as