....
    my ($class,$alias_for) = @_;
    install_sub(
        $class,
        'find_ids', 
        sub {
            my ($class,$params) = @_;
            do_something_with($alias_for);
            # $alias_for is a lexical which defined outside this sub
            # which uses deep binding so that it is available
            # when this sub is called

            return $class->SUPER::find_ids($params);
        });
     ....