this doesn't need to be a classmethod -- it can be a normal instance method

def make_val(clas,*vals):
    "this doesn't need to be a classmethod -- it can be a normal instance method"
    if clas.VALUE is None: raise TypeError('null meta-information in class for VALUE')
    clas.type_check(zip(*clas.VALUE)[1],vals,'VALUE')
    return msgpack.dumps(vals)