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: depcheck.rs
    path of file: ./repos/arrow-datafusion/datafusion/core/tests
    
    the code of the file until where you have to start completion: // Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agr
    
fn test_deps() -> Result<(), Box<dyn std::error::Error>> {
    let config = Config::default()?;
    let path = env::var("CARGO_MANIFEST_DIR").unwrap();
    let dir = Path::new(&path);
    let root_cargo_toml = dir.join("Cargo.toml");
    let workspace = cargo::core::Workspace::new(&root_cargo_toml, &config)?;
    let (_, resolve) = cargo::ops::resolve_ws(&workspace)?;

    let mut package_deps = HashMap::new();
    for package_id in resolve
        .iter()
        .filter(|id| id.name().starts_with("datafusion"))
    {
        let deps: Vec<String> = resolve
            .deps(package_id)
            .filter(|(package_id, _)| package_id.name().starts_with("datafusion"))
            .map(|(package_id, _)| package_id.name().to_string())
            .collect();
        package_deps.insert(package_id.name().to_string(), deps);
    }

    // check for circular dependencies
    for (root_package, deps) in &package_deps {
        let mut seen = HashSet::new();
        for dep in deps {
            check_circular_deps(root_package, dep, &package_deps, &mut seen);
        }
    }

    Ok(())
}