Common base class

Currently both DynamicCore and StaticCore extend HybridCore. This is a bit strange inheritance hierarchy in general, but it's especially stupid to check does a library extend any of these by using isinstance(library, HybridCore). It would be better to have a common base class named LibraryCore or RobotLibraryCore that all concrete lib cores extend. It would allow using isinstance(library, RobotLibraryCore).

Until this common base class is implemented, it's probably best to use isinstance(library, (HybridCore, DynamicCore, StaticCore)) with any generic code. That's both more explicit than just using isinstance(library, HybridCore) and also works if and when other cores don't anymore extend HybridCore.

Comece localizando as definições e os usos de HybridCore, DynamicCore e StaticCore. Analise como um LibraryCore ou RobotLibraryCore compartilhado afetaria a herança e as verificações genéricas com isinstance; considera-se concluído quando os cores concretos compartilham a nova classe base sem depender de HybridCore como tipo comum.