Macro set_attrs 

macro_rules! set_attrs {
    ($obj:expr, $vm:expr, unwrap, $($key:expr => $val:expr),+ $(,)?) => { ... };
    ($obj:expr, $vm:expr, $($key:expr => $val:expr),+ $(,)?) => { ... };
}

Macro to reduce code repetition when setting multiple attributes on an object.