modifyVolatileStorage' :: Storage
                       -> (VolatileStorageState -> VolatileStorageState)
                       -> IO ()
modifyVolatileStorage' (Storage (_, ref)) modifier =
    atomicModifyIORef' ref $ \old -> ( modifier old, () )
modifyVolatileStorage' :: Storage
                       -> (VolatileStorageState -> VolatileStorageState)
                       -> IO ()
modifyVolatileStorage' (Storage (_, ref)) modifier =
    atomicModifyIORef' ref $ \old -> ( modifier old, () )
modifyVolatileStorage' (Storage (_, ref)) modifier =
    atomicModifyIORef' ref $ \old -> ( modifier old, () )