AcDbObject：有时被覆盖的函数

自定义类有时会重写以下函数：

virtual Acad::ErrorStatus 
subErase(Adesk::Boolean erasing);
 
virtual Acad::ErrorStatus 
subHandOverTo(AcDbObject* newObject);
 
virtual Acad::ErrorStatus 
subOpen(AcDb::OpenMode mode);
 
virtual Acad::ErrorStatus 
subCancel();
 
virtual Acad::ErrorStatus 
subSwapIdWith(AcDbObjectId otherId,
              Adesk::Boolean swapXdata = false,
              Adesk::Boolean swapExtDict = false);