Java doesn't have multiple inheritance, so if you want to avoid writing the same behavior twice you instead get to write several interfaces describing the abili

Java doesn't have multiple inheritance, so if you want to avoid writing the same behavior twice you instead get to write several interfaces describing the ability to do the behaviors and write several functions in each class that implements such an interface (but does not contain the implementation) calling the functions defined in the interface on its pet InterfaceImpl. This is probably a worthwhile tradeoff, but checking in hundreds of lines of code that do literally nothing is still a bad place to be.