def cls_slots(self, cls: CLASS_OR_CLASSNAME) -> List[SlotDefinition]:
        """ Return the list of slots directly included in the class definition.  Includes slots whose
        domain is cls -- as declared in slot.domain or class.slots

        Does not include slots declared in mixins, apply_to or is_a links

        @param cls: class name or class definition name
        @return: all direct class slots
        """
        if not isinstance(cls, ClassDefinition):
            cls = self.schema.classes[cls]
        return [self.schema.slots[s] for s in cls.slots]