let button_set_transparency = GButton.button ~label:"set_transparency" ~packing:(table#attach ~left:1 ~top:5) () in
let button_load_dom = GButton.button ~label:"load from DOM" ~packing:(table#attach ~left:2 ~top:5) () in
let button_get_element_at = GButton.button ~label:"get_element_at" ~packing:(table#attach ~left:3 ~top:5) () in
let button_set_transparency = GButton.button ~label:"set_transparency" ~packing:(table#attach ~left:1 ~top:5) () in
let button_load_dom = GButton.button ~label:"load from DOM" ~packing:(table#attach ~left:2 ~top:5) () in
let button_get_element_at = GButton.button ~label:"get_element_at" ~packing:(table#attach ~left:3 ~top:5) () in