class Foo => {
    class_method 'c_foo' =>
        signature (Int, Num(5)),
        body => { ... };

    method 'foo' =>
        signature (Any, Hash),
        returns ( Int ),
        body => { ... };
};

Foo->add_post_process(
    methods => 1,
    class_methods => 0,
    action => sub { ... },
);