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/deno/cli/npm
    
    the code of the file until where you have to start completion: // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.

mod byonm;
mod cache_dir;
mod common;
mod managed;

use std::path::PathBuf;
use std::sync::Arc;

use dashmap::DashMap;
use deno_ast::Module
    
  pub async fn package_info(&self, name: &str) -> Option<Arc<NpmPackageInfo>> {
    if let Some(info) = self.info_by_name.get(name) {
      return info.value().clone();
    }
    let fetch_package_info = || async {
      let info_url = npm_registry_url().join(name).ok()?;
      let file = self
        .file_fetcher
        .fetch(&info_url, PermissionsContainer::allow_all())
        .await
        .ok()?;
      serde_json::from_slice::<NpmPackageInfo>(&file.source).ok()
    };
    let info = fetch_package_info().await.map(Arc::new);
    self.info_by_name.insert(name.to_string(), info.clone());
    info
  }