public void test_slider_set_perc (Widget widget, double percentage)
Warning: test_slider_set_perc is deprecated since "3.20".
This function will adjust the slider position of all GtkRange based widgets, such as scrollbars or scales, it’ll also adjust spin buttons.
This testing infrastructure is phased out in favor of reftests.
The adjustment value of these widgets is set to a value between the lower and upper limits, according to the
valid widget pointer.
value between 0 and 100.