# Filter: sort with `default_comparator`.
	# SEE: `sort_with` for details
	# REQUIRE: self isa Iterator[Comparable]
	#
	#     assert [1,3,2].iterator.sort.to_a	     ==  [1,2,3]
	fun sort: Iterator[E]
	do
		assert self isa Iterator[Comparable]
		var a = self.to_a
		default_comparator.sort(a)
		return a.iterator
	end