How to mock Milter.Base's -ctx object?

[heinrichheine]

Hi
i am trying to build a test for my own milter class
MyMilter(Milter.Base)

The test fails due to not set _ctx object in the milter implementation.
The _ctx is initialized by the method _setctx found in Milter/init.py but i am not sure which object i should use to initialize this in my test set up.