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_problem_info.rs
    path of file: ./repos/AtCoderProblems/atcoder-problems-backend/sql-client/tests
    
    the code of the file until where you have to start completion: use sql_client::models::{Contest, Submission};
use sql_client::problem_info::ProblemInfoUpdater;
use sql_client::simple_client::SimpleClient;
use sql_client::submission_client::SubmissionClient;
use sql_client::PgPool;
use sqlx::postgres::PgRow;
use sqlx::Row;

mod utils;

async fn get_solver(pool: &PgPool) -> Vec<(String, i32)> {
    sqlx::query("SELECT problem_id, user_count FROM solver")
        .map(|row: PgRow| {
            let problem_id: String = row.get("problem_id");
            let user_count: i32 = row.get("user_count");
            (problem_id, user_count)
        })
        .fetch_all(pool)
        .await
        .unwrap()
}

async fn get_points(pool: &PgPool) -> Vec<(String, Option<f64>)> {
    sqlx::query("SELECT problem_id, point FROM points")
        .map(|row: PgRow| {
            let problem_id: String = row.get("problem_id");
            let point: Option<f64> = row.get("po
    
async fn test_update_problem_solver_count() {
    let pool = utils::initialize_and_connect_to_test_sql().await;

    assert!(get_solver(&pool).await.is_empty());

    pool.update_submissions(&[
        Submission {
            id: 0,
            user_id: "user1".to_string(),
            result: "AC".to_string(),
            problem_id: "problem".to_string(),
            ..Default::default()
        },
        Submission {
            id: 1,
            user_id: "user2".to_string(),
            result: "AC".to_string(),
            problem_id: "problem".to_string(),
            ..Default::default()
        },
        Submission {
            id: 2,
            user_id: "user3".to_string(),
            result: "WA".to_string(),
            problem_id: "problem".to_string(),
            ..Default::default()
        },
    ])
    .await
    .unwrap();
    pool.update_solver_count().await.unwrap();
    assert_eq!(get_solver(&pool).await, vec![("problem".to_string(), 2)]);

    pool.update_submissions(&[Submission {
        id: 3,
        user_id: "user3".to_string(),
        result: "AC".to_string(),
        problem_id: "problem".to_string(),
        ..Default::default()
    }])
    .await
    .unwrap();
    pool.update_solver_count().await.unwrap();
    assert_eq!(get_solver(&pool).await, vec![("problem".to_string(), 3)]);
}