def add_add_del_on_list(key, to_add, to_remove)
      if (@is_commit)
        raise RuntimeError.new('No further request supported after a commit!')
      end
      @requests << {'add_del_on_list' => {'key' => key, 'add' => to_add, 'del'=> to_remove}}
      self
    end
def add_add_del_on_list(key, to_add, to_remove)
      if (@is_commit)
        raise RuntimeError.new('No further request supported after a commit!')
      end
      @requests << {'add_del_on_list' => {'key' => key, 'add' => to_add, 'del'=> to_remove}}
      self
    end
Adds a add_del_on_list operation to the request list.