def enter(self):
        if self.inputVolumeSelector.currentNodeID != '':
            self.logic.getFiducialsListNode(self.inputVolumeSelector.currentNodeID, self.__onFiducialsNodeModified__)
            self.logic.setActiveVolume(self.inputVolumeSelector.currentNodeID)

        if self.addFiducialButton.checked:
            self.setAddSeedsMode(True)
            # if not self.timer.isActive() \
            #         and self.logic.currentLabelmap is not None:  # Segmentation was already performed
            #     self.timer.start(500)

        self.refreshUI()
This is invoked every time that we select this module as the active module in Slicer (not only the first time)
dataset/ETHPy150Open acil-bwh/SlicerCIP/Scripted/CIP_LesionModel/CIP_LesionModel.py/CIP_LesionModelWidget.enter