Assertion: interface's implementation | /r/HasProperty | based on abstract class
Facets:
Source sentences:
text: It is not a problem to add a new method to an interface if all the implementations are based on an abstract class that you are providing, as the abstract class can give the default implementation.
text: If this is done, we return to the short answer I gave in the beginning of the article, in which method parameters should always use the interface, so they can support any implementation (based on the abstract class or not), yet the implementations should try to use the abstract class to avoid breaking changes.