`resultNow` is a function which accepts a `Deferred` and returns the result of the `Deferred`. It is an error if the `Deferred` does not have a result yet. It is intended to simplify unit tests for cases where a `Deferred` is required to have a result at a particular time.
We now have a way of doing this, that is accessible on `TestCase`.
Use cases:
The latter half of
can be rewritten more simply: