* @since 14.0
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final <V> ImmutableMap<@NonNull E, V> toMap(Function<? super E, V> valueFunction) {
    return Maps.toMap((Iterable<@NonNull E>) getDelegate(), valueFunction);
  }

  /**
   * Creates an index {@code ImmutableListMultimap} that contains the results of applying a

   * @since 14.0
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final <V> ImmutableMap<@NonNull E, V> toMap(Function<? super E, V> valueFunction) {
    return Maps.toMap((Iterable<@NonNull E>) getDelegate(), valueFunction);
  }

  /**
   * Creates an index {@code ImmutableListMultimap} that contains the results of applying a

   * Object#equals(Object)}), an {@code IllegalArgumentException} is thrown when the collection
   * operation is performed. (This differs from the {@code Collector} returned by {@link
   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(

   * the collection operation is performed. (This differs from the {@code Collector} returned by
   * {@link java.util.stream.Collectors#toMap(java.util.function.Function,
   * java.util.function.Function) Collectors.toMap(Function, Function)}, which throws an {@code
   * IllegalStateException}.)
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K extends Enum<K>, V>

   *
   * <p>If multiple input elements map to the same row and column, the specified merging function is
   * used to combine the values. Like {@link
   * java.util.stream.Collectors#toMap(java.util.function.Function, java.util.function.Function,
   * BinaryOperator, java.util.function.Supplier)}, this Collector throws a {@code
   * NullPointerException} on null values returned from {@code valueFunction}, and treats nulls

   *
   * <p>If the mapped keys contain duplicates, an {@code IllegalArgumentException} is thrown when
   * the collection operation is performed. (This differs from the {@code Collector} returned by
   * {@link Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since NEXT
   */
  public static <T extends @Nullable Object, K extends Comparable<? super K>, V>

   *
   * <p>If the mapped keys contain duplicates, an {@code IllegalArgumentException} is thrown when
   * the collection operation is performed. (This differs from the {@code Collector} returned by
   * {@link Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since NEXT
   */
  @IgnoreJRERequirement // Users will use this only if they're already using streams.

    }

    private static Map<AccessorKey, ReplacedAccessor> oldRemovedAccessorsOfUpgradedProperties(List<UpgradedProperty> upgradedProperties) {
        return upgradedProperties.stream()
            .flatMap(UpgradePropertiesRuleSetup::oldRemovedAccessorsOfUpgradedProperty)
            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));

        return getProject().getTasks()
            .withType(Test.class)
            .stream()
            .filter(Task::getEnabled)
            .collect(Collectors.toMap(Task::getPath, task -> task.getCandidateClassFiles().getFiles()));
    }

    @Input
    public Map<String, File> getTestClassNames() {
        if (testClassNames == null) {

                    .stream()
                    .filter(e -> isAttribute(e.getKey()))
                    .map(e -> new Pair<>(e.getKey(), (String) e.getValue()))
                    .collect(Collectors.toMap(Pair::getFirst, Pair::getSecond)));
            return result;
        } catch (InstantiationException | IllegalAccessException e) {
            final String msg = "Cannot create a new instance: " + entityType.getName();