I'm sorry I gave you example which uses wrong syntax. See updated node for fix. Instead of SUPER->pv it should be YourPackage->SUPER::pv. Here YourPackage is full qualified name of your subclassed package. Also you can use special token __PACKAGE__ instead of YourPackage. It will be substituted by Perl with this name.

BTW be careful with selection of package name. FYI CPAN already has Params::Validate. It is not same name but very close.

--
Ilya Martynov (http://martynov.org/)