public static <C extends Comparable> ImmutableRangeSet<C> copyOf(RangeSet<C> rangeSet) {
    checkNotNull(rangeSet);
    if (rangeSet.isEmpty()) {
      return of();
    } else if (rangeSet.encloses(Range.<C>all())) {
      return all();
    }

    if (rangeSet instanceof ImmutableRangeSet) {
      ImmutableRangeSet<C> immutableRangeSet = (ImmutableRangeSet<C>) rangeSet;
      if (!immutableRangeSet.isPartialView()) {

        return TreeRangeSet.create(contents);
      }
    },
    ImmutableRangeSetImpl {
      @Override
      <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents) {
        return ImmutableRangeSet.copyOf(contents);
      }
    };

    abstract <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents);
  }

  public enum SetMultimapImpl {
    HashMultimapImpl {
      @Override

        return TreeRangeSet.create(contents);
      }
    },
    ImmutableRangeSetImpl {
      @Override
      <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents) {
        return ImmutableRangeSet.copyOf(contents);
      }
    };

    abstract <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents);
  }

  public enum SetMultimapImpl {
    HashMultimapImpl {
      @Override