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: mod.rs
    path of file: ./repos/grafbase/engine/crates/graph-entities/src/response
    
    the code of the file until where you have to start completion: //! `QueryResponse` is an AST which aims to represent a result of a `Engine` response.
//!
//! ### Serialization & Memory Use
//!
//! We've seen a lot of memory problems with this structure on larger query responses, so we need
//! to be careful to keep both the in memory size and serialization size down.  As a result most
//! of the types in this file have some serde attrs that make
    
    fn transform_list_json() {
        let root = ResponseList::with_children(Vec::new());
        let mut response = QueryResponse::new_root(root);
        let root_id = response.root.unwrap();

        let node = response.push(root_id, ResponseContainer::new_container()).unwrap();

        let example_primitive = ResponsePrimitive::new(CompactValue::String("example".to_string()));

        response.append_unchecked(node, example_primitive, "test").unwrap();

        let output_json = serde_json::Value::Array(vec![serde_json::json!({
            "test": "example"
        })]);

        assert_eq!(response.to_json_value().unwrap().to_string(), output_json.to_string());
    }