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: lockfile.rs
    path of file: ./repos/rustsec/cargo-lock/tests
    
    the code of the file until where you have to start completion: //! Lockfile integration test

use std::str::FromStr;

// TODO(tarcieri): add more example `Cargo.lock` files which cover more scenario
    
fn serialize_v1_to_v2() {
    let mut lockfile = Lockfile::load(V1_LOCKFILE_PATH).unwrap();
    lockfile.version = ResolveVersion::V2;

    let reserialized = lockfile.to_string();
    let lockfile2 = reserialized.parse::<Lockfile>().unwrap();
    assert_eq!(lockfile.packages, lockfile2.packages);
}