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: cookbook-write-serde.rs
    path of file: ./repos/rust-csv/examples
    
    the code of the file until where you have to start completion: use std::{error::Error, io, process};

use se
    
fn example() -> Result<(), Box<dyn Error>> {
    let mut wtr = csv::Writer::from_writer(io::stdout());

    // When writing records with Serde using structs, the header row is written
    // automatically.
    wtr.serialize(Record {
        city: "Southborough".to_string(),
        region: "MA".to_string(),
        country: "United States".to_string(),
        population: Some(9686),
    })?;
    wtr.serialize(Record {
        city: "Northbridge".to_string(),
        region: "MA".to_string(),
        country: "United States".to_string(),
        population: Some(14061),
    })?;
    wtr.flush()?;
    Ok(())
}