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: mod.rs
    path of file: ./repos/uefi-rs/uefi-test-runner/src/fs
    
    the code of the file until where you have to start completion: //! Tests functionality from the `uefi::fs` module. See function [`test`].

use alloc::string::{String, ToString};
use alloc::vec::Vec;
use uefi::fs::{FileSystem, IoError, IoErrorContext, PathBuf};
use uefi::proto::media::fs::SimpleFileSystem;
use uefi::table::boot::ScopedProtocol;
use uefi::{cstr16, fs, Status};

/// Tests functionality from the `uefi::fs` module. This test relies on a
/// working File System Protocol, which is tested at a dedicated place.
pub fn test(sfs: ScopedProtocol<SimpleFileSystem>) -> Result<(), fs::Error> {
    let mut fs = FileSystem::new(sfs);

    // test create dir
    fs.create_dir(cstr16!("foo_dir"))?;

    // test write, copy, and read
    let data_to_write = "hello world";
    fs.write(cstr16!("foo_dir\\foo"), data_to_write)?;
    // He
    
fn test_copy_success(fs: &mut FileSystem) -> Result<(), fs::Error> {
    let file1_path = cstr16!("file1");
    let file2_path = cstr16!("file2");

    // Test a successful copy where the destination does not already exist.
    fs.write(file1_path, "data1")?;
    assert_eq!(fs.try_exists(file2_path), Ok(false));
    fs.copy(file1_path, file2_path)?;
    assert_eq!(fs.read(file1_path)?, b"data1");
    assert_eq!(fs.read(file2_path)?, b"data1");

    // Test that when copying a smaller file over a larger file, the file is
    // properly truncated. Also check that the original file is unchanged.
    fs.write(file2_path, "some long data")?;
    fs.copy(file1_path, file2_path)?;
    assert_eq!(fs.read(file1_path)?, b"data1");
    assert_eq!(fs.read(file2_path)?, b"data1");

    // Clean up temporary files.
    fs.remove_file(file1_path)?;
    fs.remove_file(file2_path)?;

    Ok(())
}