def METHOD_NAME(self):
    self.model.mask_model.mask_ellipse(100, 100, 20, 20)
    previous_mask = np.copy(self.model.mask_model._mask_data)
    QTest.mouseClick(self.mask_widget.grow_btn, QtCore.Qt.LeftButton)
    self.assertFalse(np.array_equal(previous_mask, self.model.mask_model._mask_data))
    QTest.mouseClick(self.mask_widget.shrink_btn, QtCore.Qt.LeftButton)
    self.assertTrue(np.array_equal(previous_mask, self.model.mask_model._mask_data))