...for coverage of the Activity-Language,
various invocations of unspecific functions must be verified,
with the additional twist that the implementation avoids indirections
and is thus hard to rig for tests.
Solution-Idea: provide a λ-mock to log any invocation into the
Event-Log helper, which was created some years ago to trace GUI communication...
...continue to proceed test-driven
...scheduler internals turn out to be intricate and cohesive,
and thus the only hope is to adhere to strict testing discipline
