ActiveModelSerializersのCollectionSerializerを使うときはネストの深さをどこで指定する？

A. renderで渡す

    @res = Hoge.where(name: hoge)
    @items = ActiveModel::Serializer::CollectionSerializer.new(
      @res,
      serializer: HogeSerializer,
      some_values: user_signed_in? && current_user.some_values
    )

    render json: {
      items: @items.page(@page),
      length: @items.size,
    }, include: ['hoge_child_a.hoge_child_child', 'hoge_child_b', 'hoge_child_c'], status: :ok