pub fn subscribe(&self) -> ReactiveHealthCheck {
        ReactiveHealthCheck {
            name: self.name,
            health_receiver: self.health_sender.subscribe(),
        }
    }
Creates a [`ReactiveHealthCheck`] attached to this updater. This allows not retaining the initial health check
returned by [`ReactiveHealthCheck::new()`].
core/lib/health_check/src/lib.rs