listDeviceClasses :: DeviceManager -> Sys [Text]
listDeviceClasses dm = atomically (Map.keys <$> readTVar (dmSubsystems dm))
listDeviceClasses :: DeviceManager -> Sys [Text]
listDeviceClasses dm = atomically (Map.keys <$> readTVar (dmSubsystems dm))
listDeviceClasses dm = atomically (Map.keys <$> readTVar (dmSubsystems dm))