[Feature Request] Partial implementation

Suppose interface A defines 2 methods `getX()` and `getY()`.
Now suppose class B implements `getX()` but doesn't implement the interface A.

I would like a warning if a class C that extends class B implements interface A (and method `getY()`) but not `getX()` (since it is already provided by the superclass).

I discovered this by trying to inline the interface A (since I noticed it had only one implementation). The IDE did that, but converted class B into an abstract class so that the "unimplemented" methods would be retained in that class.