Setting data to a QStandardItem doesn't store a reference to the object if it's datatype is a subclass of list

I am trying to set the data of a `QStandardItem`. The datatype of the data prior to the assignment is a subclass of `list`. If I try to access the object afterwards the datatype has changed to `list`.

According to the documentation a reference should be stored and that's also what I would expect in PySide2.

However, it looks like `setData` is trying to copy the object instead of storing a reference.

The behaviour only affects subclasses of list. Subclasses of dict/set/tuple work fine.
 

from PySide2 import QtGui

class Q(list):
    pass

item = QtGui.QStandardItem()
obj = Q()

type(obj)             # <class '_main_.Q'>
item.setData(obj)
type(item.data())     # <class 'list'>