newTop.right = right.removeMin(newTop);
        newTop.left = left;
        newTop.distinctElements = distinctElements - 1;
        newTop.totalCount = totalCount - oldElemCount;
        return newTop.rebalance();
      }
    }

    // Removes the minimum node from this subtree to be reused elsewhere
    private @Nullable AvlNode<E> removeMin(AvlNode<E> node) {
      if (left == null) {

    assertFalse("removeIf(x -> false) should return false", collection.removeIf(x -> false));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveIf_sometimesTrue() {
    assertTrue(
        "removeIf(isEqual(present)) should return true",
        collection.removeIf(Predicate.isEqual(samples.e0())));

    assertFalse("removeIf(x -> false) should return false", collection.removeIf(x -> false));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveIf_sometimesTrue() {
    assertTrue(
        "removeIf(isEqual(present)) should return true",
        collection.removeIf(Predicate.isEqual(samples.e0())));

    assertTrue(
        removeIf(
            list,
            new Predicate<String>() {
              @Override
              public boolean apply(String s) {
                return s.equals("b") || s.equals("d") || s.equals("f");
              }
            }));
    assertEquals(newArrayList("a", "c", "e"), list);
    assertFalse(
        removeIf(
            list,

    assertTrue(
        removeIf(
            list,
            new Predicate<String>() {
              @Override
              public boolean apply(String s) {
                return s.equals("b") || s.equals("d") || s.equals("f");
              }
            }));
    assertEquals(newArrayList("a", "c", "e"), list);
    assertFalse(
        removeIf(
            list,

    return false;
  }

  @Override
  public boolean removeAll(Collection<?> c) {
    return Iterables.removeIf(
        multimap.unfiltered().entries(),
        and(multimap.entryPredicate(), valuePredicateOnEntries(in(c))));
  }

  @Override
  public boolean retainAll(Collection<?> c) {
    return Iterables.removeIf(
        multimap.unfiltered().entries(),

        // Clean up account attempts
        accountAttempts.entrySet().removeIf(entry -> {
            AccountAttempts account = entry.getValue();
            return !account.isLockedOut() && account.getLastAttempt().plus(cleanupInterval).isBefore(now);
        });

        // Clean up IP attempts
        ipAttempts.entrySet().removeIf(entry -> {
            IpAttempts ip = entry.getValue();

        // Clean up old failure records
        long now = System.currentTimeMillis();
        lastFailureTimes.entrySet().removeIf(entry -> now - entry.getValue() > FAILURE_RECOVERY_TIME * 2);

        // Clean up old consecutive failure counters
        consecutiveFailures.entrySet().removeIf(entry -> {
            String key = entry.getKey();
            Long lastFailure = lastFailureTimes.get(key);

  }

  @Override
  public final boolean removeAll(Collection<?> oldElements) {
    throw new UnsupportedOperationException();
  }

  @Override
  public final boolean removeIf(Predicate<? super E> predicate) {
    throw new UnsupportedOperationException();
  }

  @Override
  public final boolean retainAll(Collection<?> elementsToKeep) {
    throw new UnsupportedOperationException();
  }

            throw uoe();
        }

        @Override
        public void clear() {
            throw uoe();
        }

        @Override
        public boolean removeIf(Predicate<? super E> filter) {
            throw uoe();
        }
    }

    private static UnsupportedOperationException uoe() {
        return new UnsupportedOperationException();
    }