code: func ComboBoxTextNewWithEntry() (*ComboBoxText, error) {
  	c := C.gtk_combo_box_text_new_with_entry()
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	obj := glib.Take(unsafe.Pointer(c))
  	return wrapComboBoxText(obj), nil
  }
docs: // ComboBoxTextNewWithEntry is a wrapper around gtk_combo_box_text_new_with_entry().