[jQuery] [validate] write a metadata within group

I wish use groups option to display a single message for multiple
elements, but with metadata behavior.
Something like that:
<input type="text" name="t1" class="{groups: { g1: "t1 t2"},
requered:true, number:true,messages:{required:'Please a
text.',number:'Please only numbers!'}}" />
<input type="text" name="t2" />
How to do right mode with metadata?
Thz!!