abstract Map<String, Integer> createUnfiltered();

  public void testFilteredKeysIllegalPut() {
    Map<String, Integer> unfiltered = createUnfiltered();
    Map<String, Integer> filtered = Maps.filterKeys(unfiltered, NOT_LENGTH_3);
    filtered.put("a", 1);
    filtered.put("b", 2);
    assertEquals(ImmutableMap.of("a", 1, "b", 2), filtered);

      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
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      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their

      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their

      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their

      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their

      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their

      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their

/**
 * An object representing the differences between two maps.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@DoNotMock("Use Maps.difference")
@GwtCompatible
public interface MapDifference<K extends @Nullable Object, V extends @Nullable Object> {
  /**
   * Returns {@code true} if there are no differences between the two maps; that is, if the maps are
   * equal.
   */
  boolean areEqual();

  /**

    }

    @Override
    Set<K> createKeySet() {
      @WeakOuter
      final class KeySetImpl extends Maps.KeySet<K, Collection<V>> {
        KeySetImpl() {
          super(AsMap.this);
        }

        @Override
        public boolean removeAll(Collection<?> c) {
          return removeEntriesIf(Maps.<K>keyPredicateOnEntries(in(c)));
        }

        @Override

      }
      return Maps.immutableEnumMap(map);
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // suite
  @AndroidIncompatible // test-suite builders
  public static Test suite() {
    TestSuite suite = new TestSuite();
    suite.addTest(
        MapTestSuiteBuilder.using(new ImmutableEnumMapGenerator())
            .named("Maps.immutableEnumMap")