def METHOD_NAME(
    self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer
) -> None:
    # type-ignore: mypy-zope doesn't seem to recognise that MemoryReactorClock
    # implements IReactorTime, via inheritance from twisted.internet.testing.Clock
    self.clock: IReactorTime = MemoryReactorClock()  # type: ignore[assignment]
    self.hs_clock = Clock(self.clock)
    self.url = "/_matrix/client/r0/register"
    self.registration_handler = Mock()
    self.auth_handler = Mock()
    self.device_handler = Mock()