fails:Enumerable#sort sorts by the natural order as defined by <=>
fails:Enumerable#sort yields elements to the provided block
fails:Enumerable#sort raises a NoMethodError if elements do not define <=>
fails:Enumerable#sort sorts enumerables that contain nils
fails:Enumerable#sort compare values returned by block with 0
fails:Enumerable#sort raises an error if objects can't be compared
fails:Enumerable#sort gathers whole arrays as elements when each yields multiple
