Trying to make it possible to override a Django model

gistfile1.py

from django.db.models.loading import cache
from django.db.models.base import ModelBase

import sys

def override_model(app_label, model_name):
    caller = sys._getframe(1)  # Obtain calling frame
    module_name = caller.f_globals['__name__']

    def decorator(orig_cls):
        class MyModelBase(ModelBase):
            def __new__(cls, name, bases, attrs):
                attrs['__module__'] = module_name
                if app_label in cache.app_models and model_name in cache.app_models[app_label]:
                    del cache.app_models[app_label][model_name]
                cache._get_models_cache.clear()
                return ModelBase.__new__(cls, name, bases, attrs)

        class MyModel(object):
            __metaclass__ = MyModelBase

        return type(orig_cls.__name__, (MyModel, orig_cls), {})
    return decorator