throw new InvalidObjectException("Use SerializedForm");
  }

  /**
   * Not supported. Use {@link #toImmutableBiMap} instead. This method exists only to hide {@link
   * ImmutableMap#toImmutableMap(Function, Function)} from consumers of {@code ImmutableBiMap}.
   *
   * @throws UnsupportedOperationException always

    Set<MethodSignature> missing = ImmutableSortedSet.copyOf(difference(required, found));
    if (!missing.isEmpty()) {
      fail(
          rootLocaleFormat(
              "%s should hide the public static methods declared in %s: %s",
              descendant.getSimpleName(), ancestor.getSimpleName(), missing));
    }
  }

  Object writeReplace() {
    return new SerializedForm<E>(comparator, toArray());
  }

  /**
   * Not supported. Use {@link #toImmutableSortedSet} instead. This method exists only to hide
   * {@link ImmutableSet#toImmutableSet} from consumers of {@code ImmutableSortedSet}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableSortedSet#toImmutableSortedSet}.

      @SuppressWarnings("unchecked") // safe since map is not writable
      ImmutableMap<K, V> kvMap =
          (ImmutableMap<K, V>)
              copyOfEnumMap(
                  (EnumMap<?, ? extends V>) map); // hide K (violates bounds) from J2KT, preserve V.
      return kvMap;
    }
    return copyOf(map.entrySet());
  }

  /**
   * Returns an immutable map containing the specified entries. The returned map iterates over