code: func ComboBoxNewWithEntry() (*ComboBox, error) {
  	c := C.gtk_combo_box_new_with_entry()
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	obj := glib.Take(unsafe.Pointer(c))
  	return wrapComboBox(obj), nil
  }
docs: // ComboBoxNewWithEntry() is a wrapper around gtk_combo_box_new_with_entry().