trait_mod for automatically checking and modifying arguments to methods on the fly

Resources.rakumod

    multi sub trait_mod:<is>(Method $obj, Bool :$path-checked) {
        $obj.wrap: -> $inv, $path, |c {
            if $path.starts-with: $inv.root {
                callsame;
            } else {
                callwith $inv, $inv.root ~ $path, |c;
            }
        }
    }