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: json_dynamic.rs
    path of file: ./repos/reqwest/examples
    
    the code of the file until where you have to start completion: //! This example illustrates the way to send and receive arbitrary JSON.
//!
//! This is useful for some ad-hoc experiments and situations when you don't
//! really care about the structure of the JSON and just need to display it or
//! process it at runtime.

// This is using the `tokio` runtime. You'll need 
    
async fn main() -> Result<(), reqwest::Error> {
    let echo_json: serde_json::Value = reqwest::Client::new()
        .post("https://jsonplaceholder.typicode.com/posts")
        .json(&serde_json::json!({
            "title": "Reqwest.rs",
            "body": "https://docs.rs/reqwest",
            "userId": 1
        }))
        .send()
        .await?
        .json()
        .await?;

    println!("{echo_json:#?}");
    // Object(
    //     {
    //         "body": String(
    //             "https://docs.rs/reqwest"
    //         ),
    //         "id": Number(
    //             101
    //         ),
    //         "title": String(
    //             "Reqwest.rs"
    //         ),
    //         "userId": Number(
    //             1
    //         )
    //     }
    // )
    Ok(())
}