fedorov/MultiVolumeExplorer — comment on commit cd8c08026faf1ae38adac50632bb2832de44c946
File: Py/qSlicerMultiVolumeExplorerModuleWidget.py line 22
By finetjul:

self.__logic = self.logic should work

qSlicerMultiVolumeExplorerModule (or one of its mother classes) sets the logic to the widget, so you should be able to retrieve it directly.