SerializedForm(ImmutableSortedMap<K, V> sortedMap) {
      super(sortedMap);
      comparator = sortedMap.comparator();
    }

    @Override
    Builder<K, V> makeBuilder(int size) {
      return new Builder<>(comparator);
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  @Override