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: secret.rs
    path of file: ./repos/pueue/pueue_lib/src/network
    
    the code of the file until where you have to start completion: use std::fs::File;
use std::io::prelude::*;
use std::path::Pat
    
pub fn init_shared_secret(path: &Path) -> Result<(), Error> {
    if path.exists() {
        return Ok(());
    }

    const PASSWORD_LEN: usize = 512;
    let mut rng = rand::thread_rng();

    let secret: String = std::iter::repeat(())
        .map(|()| rng.sample(Alphanumeric))
        .map(char::from)
        .take(PASSWORD_LEN)
        .collect();

    let mut file = File::create(path)
        .map_err(|err| Error::IoPathError(path.to_path_buf(), "creating shared secret", err))?;
    file.write_all(&secret.into_bytes())
        .map_err(|err| Error::IoPathError(path.to_path_buf(), "writing shared secret", err))?;

    // Set proper file permissions for unix filesystems
    #[cfg(not(target_os = "windows"))]
    {
        use std::os::unix::fs::PermissionsExt;
        let mut permissions = file
            .metadata()
            .map_err(|err| {
                Error::IoPathError(path.to_path_buf(), "reading secret file metadata", err)
            })?
            .permissions();
        permissions.set_mode(0o640);
        std::fs::set_permissions(path, permissions).map_err(|err| {
            Error::IoPathError(path.to_path_buf(), "setting secret file permissions", err)
        })?;
    }

    Ok(())
}