QComboBox Python user data crash

from PySide2 import QtWidgets

class Data(object):
    """
    Test class to store in userData. The _getitem_ is needed in order to
    reproduce the segmentation fault.
    """
    def _getitem_(self, item):
        raise ValueError("Failing")

qapp = QtWidgets.QApplication.instance()
if qapp is None:
    qapp = QtWidgets.QApplication([''])

data1 = Data()

widget = QtWidgets.QComboBox()
widget.addItem('a', data1)