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: taint_labels_rec.rs
    path of file: ./repos/semgrep/tests/rules
    
    the code of the file until where you have to start completion: async fn test(client: Client, id: String) -> Option<Json<Post>> {

    
async fn test(client: Client, id: String) -> Option<Json<Post>> {
    // `id` has label INPUT and also FORMAT at the same time, but
    // FORMAT requires INPUT. So first we need to taint it with
    // INPUT, and then we need to check again for more labels, and
    // we will realized FORMAT also applies to it.
    // ruleid: test
    client.post(format!("https://{}", id));
}