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: main.rs
    path of file: ./repos/black-hat-rust/ch_05/crawler/src
    
    the code of the file until where you have to start completion: use clap::{Command, Arg};
use std::{env, sync::Arc, time::Duration};

mod crawler;
mod error;
mod spiders;

use crate::crawler::Crawler;
use error::Error;

#[tokio::main]
async fn main() -> Result<(), anyhow::Error> {
    let cli = Command::new(clap::crate_name!())
        .version(clap::crate_version!())
        .about(clap::crate_description!())
        .subcommand(Command::new("spiders").about("List all spiders"))
        .subcommand(
            Command::new("run").about("Run a spider").arg(
                Arg::new("spider")
                    .short('s')
                    .long("spider")
                    .help("The spider to run")
                    .takes_value(true)
                    .required(true),
            ),
        )
        .arg_required_else_help(true)
        .get_matches();

    env::set_var("RUST_LOG", "info,crawler=debug");
    env_logger::init();

    if let Some(_) = cli.subcommand_matches("spiders") {
        let spider_names = vec!["cvedetails", "github", "quotes"];
        for name in spider_names {
            println!("{}", name);
        }
    } else if let Some(matches) = cli.subcommand_matches("run") {
        // we can safely unwrap as the argument is required
        let spider_name = matches.value_of("spider").unwrap();
        let crawler = Crawler::new(Duration::from_millis(200), 2, 500);

        match spider_name {
            "cvedetails" => {
                let spider = Arc::new(spiders::cvedetails::CveDetailsSpider::new());
                crawler.run(spider).await;
            }
            "github" => {
                let spider = Arc::new(spiders::github::GitHubSp
    
async fn main() -> Result<(), anyhow::Error> {
    let cli = Command::new(clap::crate_name!())
        .version(clap::crate_version!())
        .about(clap::crate_description!())
        .subcommand(Command::new("spiders").about("List all spiders"))
        .subcommand(
            Command::new("run").about("Run a spider").arg(
                Arg::new("spider")
                    .short('s')
                    .long("spider")
                    .help("The spider to run")
                    .takes_value(true)
                    .required(true),
            ),
        )
        .arg_required_else_help(true)
        .get_matches();

    env::set_var("RUST_LOG", "info,crawler=debug");
    env_logger::init();

    if let Some(_) = cli.subcommand_matches("spiders") {
        let spider_names = vec!["cvedetails", "github", "quotes"];
        for name in spider_names {
            println!("{}", name);
        }
    } else if let Some(matches) = cli.subcommand_matches("run") {
        // we can safely unwrap as the argument is required
        let spider_name = matches.value_of("spider").unwrap();
        let crawler = Crawler::new(Duration::from_millis(200), 2, 500);

        match spider_name {
            "cvedetails" => {
                let spider = Arc::new(spiders::cvedetails::CveDetailsSpider::new());
                crawler.run(spider).await;
            }
            "github" => {
                let spider = Arc::new(spiders::github::GitHubSpider::new());
                crawler.run(spider).await;
            }
            "quotes" => {
                let spider = spiders::quotes::QuotesSpider::new().await?;
                let spider = Arc::new(spider);
                crawler.run(spider).await;
            }
            _ => return Err(Error::InvalidSpider(spider_name.to_string()).into()),
        };
    }

    Ok(())
}