use std::sync::Arc;
use std::sync::Mutex;

fn main() {
    let test = Arc::new(Mutex::new("test".to_string()));
    println!("{}", test.lock().unwrap());
    {
        let mut test2 = test.lock().unwrap();
        *test2 = "test2".to_string();
    }
    println!("{}", test.lock().unwrap());
}