Ownership in Rust with Pluralize

sample.rs

fn main() {
    let s = String::from("book");
    
    // Add code here that calls the pluralize function
    let many = pluralize(s.clone());
    
    println!(
        "I have one {}, you have two {}",
        s,
        many,
    );
}

// Add appropriate parameters, return values, and implementation to this function
fn pluralize(mut a_string : String) -> String
{
    a_string.push('s');
    a_string
}