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: improvement.rs
    path of file: ./repos/stract/crates/core/src
    
    the code of the file until where you have to start completion: // Stract is an open source web search engine.
// Copyright (C) 2023 Stract ApS
//
// This program is free software: you can redistribute it 
    
    async fn new(seed_node: &str) -> Result<Self, Error> {
        let session = SessionBuilder::new().known_node(seed_node).build().await?;

        session.query("CREATE KEYSPACE IF NOT EXISTS ks WITH REPLICATION = {'class' : 'SimpleStrategy', 'replication_factor' : 1}", &[]).await?;
        session
        .query(
            "CREATE TABLE IF NOT EXISTS ks.queries (qid uuid, query text, urls text, timestamp timestamp, primary key (qid, timestamp)) WITH default_time_to_live = 7776000", // ttl 90 days
            &[],
        )
        .await?;

        session
            .query(
                "CREATE TABLE IF NOT EXISTS ks.clicks (qid uuid, click tinyint, primary key (qid)) WITH default_time_to_live = 7776000", // ttl 90 days
                &[],
            )
            .await?;

        let prepared_insert: PreparedStatement = session
            .prepare("INSERT INTO ks.queries (qid, query, urls, timestamp) VALUES(?, ?, ?, ?)")
            .await?;

        let prepared_click: PreparedStatement = session
            .prepare("INSERT INTO ks.clicks (qid, click) VALUES(?, ?)")
            .await?;

        Ok(Self {
            session,
            prepared_insert,
            prepared_click,
        })
    }