code: func (v *Notebook) GetTabLabelText(child IWidget) (string, error) {
  	c := C.gtk_notebook_get_tab_label_text(v.native(), child.toWidget())
  	if c == nil {
  		return "", errors.New("No tab label for widget")
  	}
  	return goString(c), nil
  }
docs: // GetTabLabelText() is a wrapper around gtk_notebook_get_tab_label_text().