code: def is_abstract(self) -> bool:
          
          meta_value = getattr(self.clsdict.get('Meta'), 'abstract', False)
          return self.clsdict.get(ABSTRACT_ATTR, meta_value) is True
docs: Whether or not the class-under-construction was declared as abstract (**NOTE:**
          this property is usable even *before* the :class:`MetaOptionsFactory` has run)