This chapter includes 24 problems meant to draw several rules for working with Optional. The problems and solutions presented in this section are based on the Brian Goetz (Java’s language architect) definition: Optional is intended to provide a limited mechanism for library method return types where there needed to be a clear way to represent “no result," and using null for such was overwhelmingly likely to cause errors. But, where there are rules there are exceptions as well. Therefore, do not conclude that the rules (or practices) presented here should be followed (or avoided) at all costs. Like always, it’s an it depends problem that requires to evaluate the situation and weight pros and cons.