# Pastebin VGrDKrIm
    w <- atomically do
      touched <- readTVar (touchedV agent)
      case OrderId oid `elem` touched of
        True -> pure pass
        False -> do
          v <- newEmptyTMVar
          modifyTVar' (watching agent) (MM.insert (OrderId oid) v)
          pure (atomically (takeTMVar v))