code: func (a *ACL) Free() error {
  	acl_free, err := getSymbolPointer(a.lib.handle, "acl_free")
  	if err != nil {
  		return err
  	}
  
  	ret, err := C.my_acl_free(acl_free, a.a)
  	if ret < 0 {
  		return errwrap.Wrap(errors.New("error calling acl_free"), err)
  	}
  
  	return a.lib.close()
  }
docs: // Free frees libacl's internal structures and closes libacl.