per form class, keep a Setup representer class instead of creating it at run-time for every instantiation.
introduce populate_representer.
introduce Contract::representers that encapsulates creating a representer class ONCE and allows running an each block.
introduce class-level valid_representer.
introduce input_representer.
cool: the dynamic :sync representer inherits from the original sync_representer and adds its stuff. this allows me to revert it easily if it turns out to be not useful.
introduce class save_representer. remove save |form, hash| first argument.
cleanup Save.