pub fn get<R>(&self, name: &str, mut action: impl FnMut(ShadowRef<'_, Main, Shadow>) -> R) -> R
    where
        R: PartialEq + fmt::Debug + 'static,
    {
        self.get_custom(name, |r| DivergingEq(action(r))).0
    }
Gets the specified value from both the main and shadow VM, checking whether it matches on both.
core/lib/vm_interface/src/utils/shadow.rs