@Test public void foldX(){ System.out.println(TreeSet.range(0,10).seq()); System.out.println(TreeSet.of(Comparators.naturalComparator(),0,1,2,3,4,5,6).seq()); System.out.println(HashSet.range(0,10).seq()); System.out.println(TreeSet.range(0,10).seq().foldRight(Monoids.intSum)); System.out.println(TreeSet.range(0,10).foldRight(Monoids.intSum)); }