Gtk.ComboBoxText.prototype.insert

function insert(position:Number, id:String, text:String):void {
    // Gjs wrapper for gtk_combo_box_text_insert()
}

Inserts text at position in the list of strings stored in combo_box. If id is non-null then it is used as the ID of the row. See Gtk.ComboBox:id-column.

If position is negative then text is appended.

Since 3.0