This issue is about slowly moving packages from internal/engine into internal and outside of engine. We created internal/engine when we merged https://github.com/ooni/probe-engine into https://github.com/ooni/probe-cli. We started moving packages outside internal/engine following this rule of thumb: review the package before moving, cleanup its implementation, convert to using unit tests for generating coverage. We will close this issue when internal/engine will become empty. (It will take time for this event to occur, but it is actually fine since we are basically moving packages to signal they have been code-reviewed once more and packages below internal/engine are still working as intended, just in need of a cleanup.) Once this effort is done, our code architecture would be cleaner, with flat packages inside internal and the only-historically-significant split between cli and engine would be gone forever.