[0815test]

Implementation inheritance does more than break encapsulation. It creates inherent fragility because of how it makes code defined in a base class dependent on behavior that may be overridden willy-nilly in a derived class; the possibility of overriding means that the whole bundle of public and protected methods/fields is essentially part of an object's external interface, due to its open extensibility - with method implementations typically calling through that same interface. This is far worse than what you would get with a plain old non-OOP program, even one that doesn't use encapsulation at all! In most cases, implementation inheritance can be treated as simply a bad idea that should be avoided altogether - composition is clearly the better approach.