Will inject all decorated function as methods of classkey

    classkey is some identifying string, tuple, or object

    func can also be a tuple

def decorate_class_method(func, classkey=None, skipmain=False):
    """
    Will inject all decorated function as methods of classkey

    classkey is some identifying string, tuple, or object

    func can also be a tuple
    """
    #import utool as ut
    global __CLASSTYPE_ATTRIBUTES__
    assert classkey is not None, 'must specify classkey'
    #if not (skipmain and ut.get_caller_modname() == '__main__'):
    __CLASSTYPE_ATTRIBUTES__[classkey].append(func)
    return func