Undefined function?

[steven12138]

I noticed that in engine.py:

if self.args.d_threshold and self.current_task + 1 != self.args.num_tasks and self.current_task == task_id:
    label_correct, label_total = self.update_acc_per_label(label_correct, label_total, output, target)

the self.update_acc_per_label function does not exist.

Although the code seems to work, I still wonder what this function is supposed to do and whether it is important.