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: test_verifier.rs
    path of file: ./repos/ckb/util/network-alert/src/tests
    
    the code of the file until where you have to start completion: use crate::verifier::Verifier;
use ckb_app_config::NetworkAlertConfig;
use ckb_crypto::secp::Generator;
use ckb_jsonrpc_types::JsonBytes;
use ckb_types::{packed, prelude::*};

#[test]
fn test_veirifer() {
    let keypairs: Vec<_> = (0..3).map(move |_| Generator::random_keypair()).collect();
    let config = NetworkAlertConfig {
        signatures_threshold: 2,
        public_keys: keypairs
            .iter()
            .map(|(_, pubkey)| JsonBytes::from_vec(pubkey.serialize()))
            .collect(),
    };
    let verifier = Verifier::new(config);
    let raw_alert = packed::RawAlert::new_builder().id(1u32.pack()).build();
    let hash = raw_alert.calc_alert_hash();
    let signatures
    
fn test_veirifer() {
    let keypairs: Vec<_> = (0..3).map(move |_| Generator::random_keypair()).collect();
    let config = NetworkAlertConfig {
        signatures_threshold: 2,
        public_keys: keypairs
            .iter()
            .map(|(_, pubkey)| JsonBytes::from_vec(pubkey.serialize()))
            .collect(),
    };
    let verifier = Verifier::new(config);
    let raw_alert = packed::RawAlert::new_builder().id(1u32.pack()).build();
    let hash = raw_alert.calc_alert_hash();
    let signatures = keypairs
        .iter()
        .map(|(privkey, _)| privkey.sign_recoverable(&hash.unpack()))
        .collect::<Result<Vec<_>, _>>()
        .expect("sign alert")
        .iter()
        .map(|sig| sig.serialize().pack())
        .fold(packed::BytesVec::new_builder(), |builder, item| {
            builder.push(item)
        })
        .build();
    let alert = packed::Alert::new_builder()
        .raw(raw_alert)
        .signatures(signatures)
        .build();
    assert!(verifier.verify_signatures(&alert).is_ok());
}