getCompanies(drug: Drug, env: DataFetchingEnvironment): CompletableFuture<List<Company>>? {a return env .getDataLoader<Long, List<Company>>(“key_companies_by_drugs_id”) .load(drug.companyId) }a }b val context = GraphQLContext(httpServletRequest, httpServletResponse) context.setDataLoaderRegistry( DataLoaderRegistry().register( “key_companies_by_drugs_id”, DataLoader.newDataLoader<Long, Company> { companyIds, _ -> CompletableFuture.supplyAsync { // SELECT * FROM company where company_id in (1, 2, 3) drugService.getCompanyByIds(companyIds) }d }c )b )a return context