if any(issubclass(cls, TestCase) for cls in parent_classes):

            raise Exception("Warning: '@parameterized' tests won't work "

                            "inside subclasses of 'TestCase' - use "

                            "'@parameterized.expand' instead")

        @wraps(f)

        def parameterized_helper_method(self=None):

            if self is not None and not attached_instance_method[0]:

                # confusingly, we need to create a named instance method and

                # attach that to the class...

                cls = self.__class__

                im_f = new.instancemethod(f, None, cls)

                setattr(cls, f.__name__, im_f)

                attached_instance_method[0] = True

            for args in input:

                if isinstance(args, basestring):

                    args = [args]

                # ... then pull that named instance method off, turning it into

                # a bound method ...

                if self is not None:

                    args = [getattr(self, f.__name__)] + list(args)

                else:

                    args = [f] + list(args)

                # ... then yield that as a tuple. If those steps aren't

                # or doesn't run setup methods.

                yield tuple(args)

        f.__name__ = "_helper_for_%s" % (f.__name__,)

        parameterized_helper_method.parameterized_input = input

        parameterized_helper_method.parameterized_func = f

        return parameterized_helper_method

    return parameterized_helper

def to_safe_name(s):

    return re.sub("[^a-zA-Z0-9_]", "", s)

def parameterized_expand_helper(func_name, func, args):

    def parameterized_expand_helper_helper(self=()):

        if self != ():

            self = (self,)

        return func(*(self + args))

    parameterized_expand_helper_helper.__name__ = str(func_name)

    return parameterized_expand_helper_helper