An error occurs when you remove the interface


<img width="633" alt="image" src="https://user-images.githubusercontent.com/13673313/177098234-adc48421-643a-4a5c-95e3-cfc3e2d211ea.png">

<img width="1407" alt="image" src="https://user-images.githubusercontent.com/13673313/177097995-4a5c174c-b900-4b8f-90d5-725546e46d81.png">

Is there something wrong with my usage?
