Please override validate_with()

[Benct Philip Jonsson]

I'd be grateful if PVD would override validate_with() as well as validate() so that one can pass a 'dependencies' param to it. validate_with(), and in particular its 'called' param, are very useful if you want to validate a subhash of the params, or if you get the params as a hashref. validate(@{[%$p]}, ...) -- ugh no please! To be sure one can test against an *_of object after validation with validate_with(), but that's kind of clunky!