Tests with mocked responses are easy to write, quick to run, stable, and focused. We should prefer them where possible. This task encompasses the work to convert one existing test from a live network request to a mocked response so we'll have a good pattern to follow for the remaining tests.

Similarly, @Jdlrobson writes:

A lot of the logic in MCSs methods is tested only by tests that run against the response of the api. This makes running npm test slow which makes it hard to do big refactors.

I'd like to create some unit tests for existing functionality.