We have a requirement that we have only one value with a given key in each namespace, but currently we do not have tests for that and likely do not ensure that. Would be nice to add the tests for that and fix an implementation if it's not a case.

The first action in this issue will be to introduce set of tests that checks that values with the duplicated keys are not stored in the scls format. It seems that we need to either use MultiNamespace tests or introduce a new module spec.