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/spyglass/crates/spyglass/src/crawler
    
    the code of the file until where you have to start completion: use addr::parse_domain_name;
use anyhow::Result;
use chrono::prelude::*;
use chrono::Duration;
use entities::models::tag::TagPair;
use entities::models::tag::TagType;
use entities::models::{crawl_queue, fetch_history};
use entities::sea_orm::prelude::*;
use governor::clock::QuantaClock;
use governor::state::keyed::DashMapStateStore;
use governor::Quota;
use governor::RateLi
    
    pub fn new(queries_per_second: u32) -> Self {
        let client = reqwest::Client::builder()
            .user_agent(APP_USER_AGENT)
            // TODO: Make configurable
            .connect_timeout(std::time::Duration::from_secs(3))
            .timeout(std::time::Duration::from_secs(30))
            .build()
            .expect("Unable to create reqwest client");

        let qps = if let Some(num) = NonZeroU32::new(queries_per_second) {
            num
        } else {
            nonzero!(2u32)
        };

        let quota = Quota::per_second(qps);

        Crawler {
            client,
            limiter: Arc::new(RateLimiter::<String, _, _>::keyed(quota)),
        }
    }