@lazy(-2)
def f():
    return 56

print([f() for _ in range(10)])

I think you agree it shouldn't do this:

[56, None, 56, 56, 56, 56, 56, 56, 56, 56]

For i=2, j=5 it should be a normal function (ie. 56). And the test case should support that. The asserted value is found with val = 56 if j%i else None, which evaluates to 56.

Could you post the solution you are trying to make work?