>If `Maybe` is an output then existing callers SHOULD be broken, because they must now handle a new possibility of failure they didn't before. Look at the exam

>If `Maybe` is an output then existing callers SHOULD be broken, because they must now handle a new possibility of failure they didn't before. Look at the example again. The output was Maybe y "yesterday", "today" the output is y. Existing callers shouldn't have to change - there is no new possibility they need to handle - they no longer need to deal with the possibility of Nothing.