* the values.
     */
    private final Range<Cut<C>> complementLowerBoundWindow;

    ComplementRangesByLowerBound(NavigableMap<Cut<C>, Range<C>> positiveRangesByLowerBound) {
      this(positiveRangesByLowerBound, Range.<Cut<C>>all());
    }

    private ComplementRangesByLowerBound(
        NavigableMap<Cut<C>, Range<C>> positiveRangesByLowerBound, Range<Cut<C>> window) {