code: def check_important_sub_metrics(self, sub_metric):
      
      if not self.important_sub_metrics:
        return False
      if sub_metric in self.important_sub_metrics:
        return True
      items = sub_metric.split('.')
      if items[-1] in self.important_sub_metrics:
        return True
      return False
docs: check whether the given sub metric is in important_sub_metrics list