Function handle 

pub async fn handle<S, B>(state: &S, request: Request<B>) -> Response<Bytes>
where
    S: State,
    B: Body<Data = Bytes>,
    B::Error: Into<Box<dyn Error + Send + Sync>>,

Answer a request to the REST API.

The path is the API’s own – /items, /rpc/f – with whatever prefix the host mounted it under already taken off. The body is read here, after the token has been checked, and no further than max_body_size.