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,

      if (entryPredicate.apply(entry) && Objects.equals(entry.getValue(), o)) {
        unfilteredItr.remove();
        return true;
      }
    }
    return false;
  }

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

  @Override

   * removeFrom.removeIf(predicate)} instead.
   *
   * @param removeFrom the iterable to (potentially) remove elements from
   * @param predicate a predicate that determines whether an element should be removed
   * @return {@code true} if any elements were removed from the iterable
   * @throws UnsupportedOperationException if the iterable does not support {@code remove()}.
   * @since 2.0
   */

  @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();
  }

  @Override
  public final void clear() {

   * removeFrom.removeIf(predicate)} instead.
   *
   * @param removeFrom the iterable to (potentially) remove elements from
   * @param predicate a predicate that determines whether an element should be removed
   * @return {@code true} if any elements were removed from the iterable
   * @throws UnsupportedOperationException if the iterable does not support {@code remove()}.
   * @since 2.0
   */

   * otherwise, this method returns false.
   */
  boolean remove(K key, long value) {
    return map.remove(key, value);
  }

  /**
   * Atomically remove {@code key} from the map iff its associated value is 0.
   *
   * @since 20.0
   */
  @CanIgnoreReturnValue
  public boolean removeIfZero(K key) {
    return remove(key, 0);
  }

  /**

   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final boolean removeIf(Predicate<? super E> filter) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the collection unmodified.
   *