def METHOD_NAME(self):
    data = Orange.data.Table("iris.tab")
    self.send_signal(OWIntegrate.Inputs.data, data)
    self.widget.add_preprocessor(pack_editor(IntegrateSimpleEditor))
    self.widget.show_preview()
    wait_for_preview(self.widget)
    self.assertEqual(0, len(self.widget.curveplot.markings))
    self.widget.flow_view.set_preview_n(0)
    self.widget.show_preview()
    wait_for_preview(self.widget)
    self.assertGreater(len(self.widget.curveplot.markings), 0)