Function procedure_feed 

pub fn procedure_feed<T>(
    items: Pin<Box<dyn Stream<Item = Result<T, CratestackError>> + Send>>,
) -> Pin<Box<dyn Stream<Item = Result<Value, CratestackError>> + Send>>
where
    T: Serialize + Send + 'static,

A handler’s items encoded to JSON values, ending after the first error.