def assert_selection_valid(self):
    try:
        self.guiScene[self._bs.name]
        return True
    except:
        print('Please select a ballast system first')
        return False
def assert_selection_valid(self):
    try:
        self.guiScene[self._bs.name]
        return True
    except:
        print('Please select a ballast system first')
        return False