Proprietary license

What are the terms of the "Proprietary" license mentioned in the setup.py?

Legally what gives me the right to even read the source code in this repository?

I see https://github.com/Shoobx/migrant/ is also the same.

But many repos in this org are MIT.  Could these other projects also be MIT, or even something very restrictive like AGPL.