+ methods and other class attributes do not change after startup
+ single inheritance is fully supported
-+ simple mixins somewhat work too, but the mixed in class needs a
- ``_mixin_ = True`` class attribute. isinstance checks against the
- mixin type will fail when translated.
++ use `rpython.rlib.objectmodel.import_from_mixin(M)` in a class
+ body to copy the whole content of a class `M`. This can be used
+ to implement mixins: functions and staticmethods are duplicated
+ (the other class attributes are just copied unmodified).
+ classes are first-class objects too