def initialize_fields(self):
        """
        The dict self.base_fields is a model instance at this point.
        Turn it into an instance attribute on this meta class.
        Also intitialize any other special fields if needed in sub-classes.

        :return: None
        """
        for field in dir(self):
            obj = getattr(self, field)
            if isinstance(obj, Field):
                self._meta.fields[field] = obj