>It didn't, of course, resolve the problem of the thread as how to use one generic method of updating properties that may exist only for some classes. I will look closer at your suggestion and also try to discuss this problem in our group.
seems in the "default method area" java is actually ahead of C#. From the limited fooling around I have to say that adding mixin/behavioural multiple inheritance in Java for me now feels even better than the implementation in Python, as the compiler error on duplicate default method names in Java really helps by turning the spotlight to potential problem. Those few edge cases probably are better served by asking for a definite impementation and not fall back on the definition order.
Easiest coding would be to enhance your OperatorSession static class with methods, but calling them might be considered a tightly coupled dependency, which clearly is an antipattern from architectural POV.
