def setUp(self): with open_widget_classes(): class OWSaveMockWriter(OWSave): writer = Mock() writer.EXTENSIONS = [".csv"] writer.SUPPORT_COMPRESSED = True writer.SUPPORT_SPARSE_DATA = False writer.OPTIONAL_TYPE_ANNOTATIONS = False self.widget = self.create_widget(OWSaveMockWriter) # type: OWSave self.iris = Table("iris")