this.delegate = delegate;
    }

    @Override
    protected Map<K, V> delegate() {
      return delegate;
    }

    @Override
    public Set<K> keySet() {
      return new ForwardingSet<K>() {
        @Override
        protected Set<K> delegate() {
          return delegate.keySet();
        }

        @Override
        public Iterator<K> iterator() {

      this.delegate = delegate;
    }

    @Override
    protected Map<K, V> delegate() {
      return delegate;
    }

    @Override
    public Set<K> keySet() {
      return new ForwardingSet<K>() {
        @Override
        protected Set<K> delegate() {
          return delegate.keySet();
        }

        @Override
        public Iterator<K> iterator() {

        cast(getKey(), value);
        return super.setValue(value);
      }
    };
  }

  @Override
  public Set<Entry<Class<? extends @NonNull B>, B>> entrySet() {
    return new ForwardingSet<Entry<Class<? extends @NonNull B>, B>>() {

      @Override
      protected Set<Entry<Class<? extends @NonNull B>, B>> delegate() {
        return MutableClassToInstanceMap.this.delegate().entrySet();
      }

              .that(immutableCopy)
              .isIn(distinctCandidatesByAscendingSize);
        }
      }
    }
  }

  private static final class MutatedOnQuerySet<E> extends ForwardingSet<E> {
    final Iterator<ImmutableSet<E>> infiniteCandidates;

    MutatedOnQuerySet(Iterable<ImmutableSet<E>> infiniteCandidates) {
      this.infiniteCandidates = infiniteCandidates.iterator();
    }

    CountingSupplier<Set<Integer>> factory =
        new SetSupplier() {
          @Override
          public Set<Integer> getImpl() {
            Set<Integer> backing = super.getImpl();
            return new ForwardingSet<Integer>() {
              @Override
              protected Set<Integer> delegate() {
                return backing;
              }

              @Override

    public NavigableMap<K, V> descendingMap() {
      return asMap(set.descendingSet(), function);
    }
  }

  private static <E extends @Nullable Object> Set<E> removeOnlySet(Set<E> set) {
    return new ForwardingSet<E>() {
      @Override
      protected Set<E> delegate() {
        return set;
      }

      @Override
      public boolean add(@ParametricNullness E element) {

    public NavigableMap<K, V> descendingMap() {
      return asMap(set.descendingSet(), function);
    }
  }

  private static <E extends @Nullable Object> Set<E> removeOnlySet(Set<E> set) {
    return new ForwardingSet<E>() {
      @Override
      protected Set<E> delegate() {
        return set;
      }

      @Override
      public boolean add(@ParametricNullness E element) {