}

    @Override
    public SortedMap<K, V> headMap(@ParametricNullness K toKey) {
      return headMap(toKey, false);
    }

    @Override
    public NavigableMap<K, V> headMap(@ParametricNullness K toKey, boolean inclusive) {
      return Maps.unmodifiableNavigableMap(delegate.headMap(toKey, inclusive));
    }

    @Override

    }

    @Override
    public SortedMap<K, V> headMap(@ParametricNullness K toKey) {
      return headMap(toKey, false);
    }

    @Override
    public NavigableMap<K, V> headMap(@ParametricNullness K toKey, boolean inclusive) {
      return Maps.unmodifiableNavigableMap(delegate.headMap(toKey, inclusive));
    }

    @Override