You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: error.rs
    path of file: ./repos/rust-template/rust+wasm/{{project-name}}/src.axum
    
    the code of the file until where you have to start completion: //! Generic result/error resprentation(s).

use axum::{
    http::StatusCode,
    response::{IntoResponse, Response},
    Json,
};

use serde::{Deserialize
    
    fn test_not_found() {
        let id = Ulid::new();
        let err = AppError::not_found(id);

        assert_eq!(err.status, StatusCode::NOT_FOUND);
        assert_eq!(
            err.title,
            StatusCode::NOT_FOUND
                .canonical_reason()
                .map(|r| r.to_string())
        );
        assert_eq!(
            err.detail.unwrap(),
            format!("Entity with id {id} not found")
        );
    }