@overrides(SettingsMigrator)
def migrate_from_1_to_2(self, settings):
    self.assertEqual(self._old_settings, settings)
    self._from_1_to_2_called = True
    settings[SettingsMigrator.SETTINGS_VERSION] = 2
@overrides(SettingsMigrator)
def migrate_from_1_to_2(self, settings):
    self.assertEqual(self._old_settings, settings)
    self._from_1_to_2_called = True
    settings[SettingsMigrator.SETTINGS_VERSION] = 2