I'll add a comment explaining:

        // Calling super.rebind last because want serverPoolMemberTrackerPolicy to be set.
        // Otherwise, connectSensors throws NPE (when it's called by callRebindHooks(),
        // called by super.rebind()).
        // TODO This still feels risky - could policy kick off code before super.rebind gets
        // a chance to do its important initialisation, thus causing NPE or some such?!