def METHOD_NAME(self):
    self.widget = self.create_widget(self.widget_cls)
    data = Table("iris")
    self.send_signal(self.widget.Inputs.data, data)
    self.widget.add_preprocessor(pack_editor(WarningEditor))
    self.editor = self.widget.flow_view.widgets()[0]
    self.assertIsInstance(self.editor, WarningEditor)