gistfile1.txt

use ClassX::StrictConstructor;

class A {
    method new {
        say "new from A"
    }
}

class B is A does ClassX::StrictConstructor {
    has $.a;
    
    method new(*%attrs) {
        say "new from B";
        self.ClassX::StrictConstructor::new(|%attrs);
    }
}

B.new(a => 5);