For example, the class FileStorage defines a $data property, and the class WDDXStorage also defines a similar property which will not override the one in the object acquired during instantiation from the class FileStorage.
One point that we have not mentioned above, is that the process of aggregation will not override existing properties or methods in the objects. For example, the class FileStorage defines a $data property, and the class WDDXStorage also defines a similar property which will not override the one in the object acquired during instantiation from the class FileStorage.