Macro model::model

macro_rules! model {
    (
        Model => $model:stmt,
        Implementation => $implementation:stmt,
        $($op:ident ($($type:ty),*) ($parm:pat in $strategy:expr) => $body:expr),*
    ) => { ... };
    (
        Config => $config:expr,
        Model => $model:stmt,
        Implementation => $implementation:stmt,
        $($op:ident ($($type:ty),*) ($parm:pat in $strategy:expr) => $body:expr),*
    ) => { ... };
}