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: lib.rs
    path of file: ./repos/rules_rust/examples/crate_universe/vendor_remote_manifests/src
    
    the code of the file until where you have to start completion: use std::path::Path;

use tokio::fs::File;
use tokio::io::{AsyncBufReadExt, BufReader};

pub async fn fill_buf_file(path: &Path) -> Vec<u8> {
    let file = File::open(path).await.unwrap();
    let mut file = BufReader::new(file);

    let mut contents = Vec::new();

    loop {
        let consumed = {
            let buffer = file.fill_buf().await.unwrap();
            if buffer.is_empty() {
                break;
          
    
pub async fn fill_buf_file(path: &Path) -> Vec<u8> {
    let file = File::open(path).await.unwrap();
    let mut file = BufReader::new(file);

    let mut contents = Vec::new();

    loop {
        let consumed = {
            let buffer = file.fill_buf().await.unwrap();
            if buffer.is_empty() {
                break;
            }
            contents.extend_from_slice(buffer);
            buffer.len()
        };

        file.consume(consumed);
    }

    contents
}