struct Connection;

struct Pool
{
    connection: Connection,
}

impl Pool {
    fn new () -> Pool
    {
        Pool {
            connection: Connection{},
        }
    }

    fn connection(&self) -> &Connection
    {
        &self.connection
    }
}

struct Model<'a>
{
    connection: &'a Connection,
}

impl<'a> Model<'a>
{
    fn new(pool: &Pool) -> Model<'a>
    {
        Model {
            connection: pool.connection()
        }
    }
}

fn main() {
    let pool = Pool::new();
    let model1 = Model::new(&pool);
    let model2 = Model::new(&pool);
}