In the tests, we create a lot of Recipient{}s, and that ends up being
very verbose and sometimes cumbersome.
Also, if we ever want to extend it, it would result in a lot of
unnecessary refactoring.
So this patch replaces the Recipient{} instantiations with helper
functions, to help readability and extendability.
This only affects the tests, and there are no changes to them either, it
is purely a refactor.
964a2a8f75