How can we save per-class metrics to a file?

[davidhuangal]

When performing testing, the per-class metrics are displayed in a PrettyTable, but they are not saved to disk anywhere. Is there a setting for this or does this feature not exist? I believe that it used to exist, but it seems like a lot of quality of life features were removed when moving to MMSegmentation >= 1.0.0 for no reason...

I'm using an IoUMetric evaluator like so:

test_evaluator = dict(type="IoUMetric", iou_metrics=["mIoU", "mFscore"])