def METHOD_NAME(self):
    d = self.new_dict()
    # setting a key with dict.setdefault() must change the version
    self.check_version_changed(d, d.setdefault, 'key', 'value1')
    # don't change the version if the key already exists
    self.check_version_dont_change(d, d.setdefault, 'key', 'value2')