👉 Retainability is a concept in software engineering that refers to the ability of an object or resource to be reused and recycled. It is based on the principle that objects should have some kind of "memory" or "storage" so that they can be used again with less effort, without having to create new copies. In other words, retainable objects are those that can be modified by others without affecting their original state. This means that objects can only be accessed and manipulated using the same methods as