[sidlls]

No, you don’t, unless you’re of the opinion that actual data structures with test data should not be used in a unit test.

[bb88]

I think you're missing the point here.

Duck typing with python (e.g.) makes it easy to mock a class. One can subclass a Java class to make a mock, etc.

One can't do that in golang unless it's through an interface which then decouples tightly coupled code because [golang reasons].