func handleGet() upfront.Handler[ResponseType, ErrorType] {
	return func(in upfront.Request) upfront.Result[ResponseType, ErrorType] {
		// `in` will contain your normall *http.Request

		// Use `upfront.OKResult` or `upfront.ErrResult` to return a status code
		// along with either the left or right type paramters
		return upfront.OKResult[ResponseType, ErrorType](
			val,
			http.StatusOK,
		)
	}
}

func handlePost() upfront.BodyHandler[Body, ResponseType, ErrorType] {
	return func(in upfront.BodyRequest[Record]) upfront.Result[Record, APIError] {
		// `in` not only has your `*http.Request`, but also has your `Body` type
		// in there as well

		// Do something with `in.Body`...

		// Maybe something has gone wrong
		return upfront.Err[Body, ResponseType, ErrorType](
			ErrorType{
				Err: err,
			},
			http.StatusInternalServerError,
		)
	}
}