#[derive(Debug)]
struct A
{
    b: B,
}

impl A
{
    fn new() -> A
    {
        A
        {
            b: B::new(),
        }
    }

    fn foo(&mut self)
    {
        {
        let b = &mut self.b;
        b.foo();
        }
        self.baz();
    }

    fn baz(&self) -> String
    {
        String::from("Qux")
    }
}

#[derive(Debug)]
struct B
{
    b1: String,
}

impl B
{
    fn new() -> B
    {
        B
        {
            b1: String::from(""),
        }
    }

    fn foo(&mut self)
    {
        self.b1 = String::from("Foo");
    }
}

fn main()
{
    let mut a = A::new();
    a.foo();

    println!("{:?}", &a);
}