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: notifications.rs
    path of file: ./repos/rustup/src/utils
    
    the code of the file until where you have to start completion: use std::fmt::{self, Display};
use std::path::Path;

use url::Url;

use crate::utils::notify::NotificationLevel;
use crate::utils::units::{self, Unit};

#[derive(Debug)]
pub enum Notification<'a> {
    CreatingDirectory(&'a str, &'a Path),
    LinkingDirectory(&'a Path, &'a Path),
    CopyingDirectory(&'a Path, &'a Path),
    RemovingDirectory(&'a str, &'a Path),
    DownloadingFile(&'a Url, &'a Path),
    /// Received the Content-Length of the to-be downloaded data.
    DownloadContentLengthReceived(u64),
    /// Received some data.
    DownloadDataReceived(&'a [u8]),
    /// Download has fini
    
    pub(crate) fn level(&self) -> NotificationLevel {
        use self::Notification::*;
        match self {
            SetDefaultBufferSize(_) => NotificationLevel::Debug,
            CreatingDirectory(_, _)
            | RemovingDirectory(_, _)
            | LinkingDirectory(_, _)
            | CopyingDirectory(_, _)
            | DownloadingFile(_, _)
            | DownloadContentLengthReceived(_)
            | DownloadDataReceived(_)
            | DownloadPushUnit(_)
            | DownloadPopUnit
            | DownloadFinished
            | ResumingPartialDownload
            | UsingCurl
            | UsingReqwest => NotificationLevel::Verbose,
            RenameInUse(_, _) => NotificationLevel::Info,
            NoCanonicalPath(_) => NotificationLevel::Warn,
            Error(_) => NotificationLevel::Error,
        }
    }