code: def purgeDeletedWidgets():
          
          toremove = []
          for field in AbstractEditorWidget.funit_fields:
              if sip.isdeleted(field):
                  toremove.append(field)
          for field in toremove:
              AbstractEditorWidget.funit_fields.remove(field)
  
          toremove = []
          for field in AbstractEditorWidget.tunit_fields:
              if sip.isdeleted(field):
                  toremove.append(field)
          for field in toremove:
              AbstractEditorWidget.tunit_fields.remove(field)
docs: Finds old references to stashed fields and deletes them