code: func (v *ComboBoxText) Insert(position int, id, text string) {
  	cid := C.CString(id)
  	ctext := C.CString(text)
  	defer C.free(unsafe.Pointer(cid))
  	defer C.free(unsafe.Pointer(ctext))
  	C.gtk_combo_box_text_insert(v.native(), C.gint(position), (*C.gchar)(cid), (*C.gchar)(ctext))
  }
docs: // Insert is a wrapper around gtk_combo_box_text_insert().