github seems to have lost this discussion, but this works for me:


```
In [1]: class A:
   ...:     @property
   ...:     def b(self):
   ...:         return []
   ...:     

In [2]: a = A()

In [3]: isinstance(a.b, list)
Out[3]: True

In [4]: isinstance(a.b, (list, tuple))
Out[4]: True
```