Macro new_mac_test 

macro_rules! new_mac_test {
    ($name:ident, $mac:ty, $test_fn:ident $(,)?) => { ... };
    ($name:ident, $mac:ty, $test_fn:ident, trunc_left $(,)?) => { ... };
    ($name:ident, $mac:ty, $test_fn:ident, trunc_right $(,)?) => { ... };
    ($name:ident, $mac:ty, $test_fn:ident, $trunc:expr $(,)?) => { ... };
}

Define MAC test