#eval rbtree.from_list [3, 4, 2, 5, 1] (<)
#eval rbtree.from_list [3, 4, 2, 5, 1] (>)
#eval (rbtree.from_list [3, 4, 2, 5]).to_list
#eval rbtree.from_list [3, 4, 2, 5]
#eval rbtree.to_list $ rbtree.from_list [3, 4, 2, 5]
