Basically a summary of what have been said about OO design

The deadly diamond shape inheritance relationship.

That’s why Java uses multiple interface instead.

To inherit the implementation but not the interface.

Example:

A template should be used to generate a collection of classes when the type of the objects does not affect the behavior of the class’s functions.

Layering is known as composition, containment, and embedding.

It represents a ‘has-a’ relationship