Apollo GraphQL：动态缓存模式类型，而不是整个解析器

问：

我想使用动态缓存。我能够将缓存 maxAge 设置到查询解析器中，但由于解析器可以同时返回不成功和成功的响应，因此我只想缓存成功的响应。为此，我想仅为 SearchResultProductItem 设置信息缓存值。这是我的架构：

type SearchResultSuccessfulResponse {
  "Set true false for the response of the API"
  success: Boolean!
  searchResult: SearchResult!
}

union SearchProductsResponse = GenericResponse | SearchResultSuccessfulResponse

type SearchResult {
  searchResultItem: [SearchResultProductItem!]!
}

"Product details"
type SearchResultProductItem {
  "Product id"
  globalMaterialID: ID!
}

type Query {
  "Search products"
  searchProducts(searchRequest: SearchRequest!): SearchProductsResponse!
}

现在解析器是这样的：

Query: {
        searchProducts: async (_, args: QuerySearchProductsArgs, context, info) => {
          // info.cacheControl.setCacheHint({ maxAge: context.cacheMaxAge, scope: "PRIVATE" })
          try {
            const result = await (context.datasourceApiMap[ProductAPI.apiName] as ProductAPI).searchProducts(
              args.searchRequest,
            )
            return {
              success: true,
              searchResult: result,
            }
          } catch (error: any) {
            return {
              success: false,
              errorCode: (error.extensions && error.extensions.code) ?? "PRODUCTS_NOT_FOUND",
              errorMessage: error.message,
            }
          }
        },
      },
      SearchProductsResponse: {
        __resolveType(response) {
          if (response.success) {
            return "SearchResultSuccessfulResponse"
          }
          if (!response.success) {
            return "GenericResponse"
          }
          return null
        },
      },

如何为唯一的 SearchResultProductItem 类型编写解析程序？