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: main.rs
    path of file: ./repos/mun/examples/fibonacci/rust/src
    
    the code of the file until where you have to start completion: use mun_runtime::Runtime;
use std::env;

fn main() {
    let lib_dir = env::args().nth(1).expect("Expected path to a Mun library.");
    println!("lib: {}", lib_dir);

    // Safety: we assume here that the library passed on the commandline is safe.
    let mut runtime =
        unsafe { Runtime::builder(lib_dir).finish() }.expect("Failed to spawn Runtime");

    loop {
        let n: i64 = runtime
            .invoke("nth", ())
            .unwrap_or_else(|e| e.wait(&mut runtime));
        let result: i64 = runtime
            .invoke("fibonacci", (n,))
            .unwrap_or_else(|e| e.wait(&mut runtime));
        pr
    
fn main() {
    let lib_dir = env::args().nth(1).expect("Expected path to a Mun library.");
    println!("lib: {}", lib_dir);

    // Safety: we assume here that the library passed on the commandline is safe.
    let mut runtime =
        unsafe { Runtime::builder(lib_dir).finish() }.expect("Failed to spawn Runtime");

    loop {
        let n: i64 = runtime
            .invoke("nth", ())
            .unwrap_or_else(|e| e.wait(&mut runtime));
        let result: i64 = runtime
            .invoke("fibonacci", (n,))
            .unwrap_or_else(|e| e.wait(&mut runtime));
        println!("fibonacci({}) = {}", n, result);

        // Safety: we assume the updates are safe.
        unsafe { runtime.update() };
    }
}