This test doesn't compile in a way that reveals a problem with the design. The
verification service takes a `Request<'msg>` parameterized by the message
lifetime, and returns a future unconstrained by the message lifetime (it hashes
upfront to avoid requiring that `'msg` outlive `call`). But the `Batch`
middleware has the verification service working on its own task, so how can we
ensure that the message lives long enough to be read by the worker task?
Jane Lusby
Jane Lusby
Henry de Valence