what is the argument regress_weight for?

[geobao]

你好, I would like to know what is the meaning of this line:

regress_weight=dict(type='iou')),

It is in the config file, here
I find it confusing because the regression loss is already set as ProbiouLoss with mode L1 and loss_weight=1 as per:

regress=[dict(type='ProbiouLoss', mode='l1', loss_weight=1.0)],

So what is the argument regress_weight for?

谢谢