this.upperBoundWindow = upperBoundWindow;
    }

    private NavigableMap<Cut<C>, Range<C>> subMap(Range<Cut<C>> window) {
      if (window.isConnected(upperBoundWindow)) {
        return new RangesByUpperBound<>(rangesByLowerBound, window.intersection(upperBoundWindow));
      } else {
        return ImmutableSortedMap.of();
      }
    }

    @Override