Multiscale Object Detection

AttributeError: module 'd2l.torch' has no attribute 'multibox_prior'

I have !pip install -U git+
Why did it happen?

It runs well on my computer, but got bugs on colab.


Would appreciate it if someone could shed some more light on this statement -

Since the midpoints of anchor boxes anchors overlap with all the units on feature map fmap, the relative spatial positions of the midpoints of the anchors on any image must have a uniform distribution.

Why the uniform distribution condition must be met with?