Discovering multiple inheritance in Java with the twin pattern

This pattern allows you to combine functions of objects that tend to be used together, which is a common paradigm used by languages without multiple inheritance support.

Motivation

The twin pattern presents the possibility to implement multiple inheritance in Java. Multiple inheritance is not a supported concept as it may lead to compiler inconsistency, known as the diamond problem. The diamond problem defines a state through class abstraction where the compiler may turn out to be inconsistent. This state is due to the lack of information due to multiple abstract classes. The compiler does not have enough information about which methods should execute.

Sample code

This pattern is not supported by the platform and is rarely required for development. For these reasons, the pattern most likely does not exist inside the released JDK, as described. However, let us examine a possible example to better understand the...