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: tutorial-write-serde-01.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};

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

    // We still need to write headers manually.
    wtr.write_record(&[
        "City",
        "State",
        "Population",
        "Latitude",
        "Longitude",
    ])?;

    // But now we can write records by providing a normal Rust value.
    //
    // Note that the odd `None::<u64>` syntax is required because `None` on
    // its own doesn't have a concrete type, but Serde needs a concrete type
    // in order to serialize it. That is, `None` has type `Option<T>` but
    // `None::<u64>` has type `Option<u64>`.
    wtr.serialize((
        "Davidsons Landing",
        "AK",
        None::<u64>,
        65.2419444,
        -165.2716667,
    ))?;
    wtr.serialize(("Kenai", "AK", Some(7610), 60.5544444, -151.2583333))?;
    wtr.serialize(("Oakman", "AL", None::<u64>, 33.7133333, -87.3886111))?;

    wtr.flush()?;
    Ok(())
}