Create a layer of model element handlers that would contain a logic regarding structure of model elements, like for removal including dependencies etc., instead of merging it all in a single method in controller or "adapter". This can be either class-per-model-type (OPPetriNetTransitionHandler) same as with controllers and diagram elements, or class-per-operation-and-plugin (OPPetriNetRemovalService).
Create a layer of model element handlers that would contain a logic regarding structure of model elements, like for removal including dependencies etc., instead of merging it all in a single method in controller or "adapter". This can be either class-per-model-type (OPPetriNetTransitionHandler) same as with controllers and diagram elements, or class-per-operation-and-plugin (OPPetriNetRemovalService).