<Response header has duplicated values> I have two...

# stackoverflow

[user]

Response header has duplicated values
I have two simple microservices through which the download file flows, but for some unknown reason some header values are duplicated.
First service where is Response build:
@POST
@Path(PRINT_PREVIEW)
fun print(@Valid printRequest: PrintRequest): Response {

// printPreview is Pair
val printPreview = printService.printPreview(printRequest)

return Response.ok(printPreview.second)
.header("Content-Disposition", "attachment; filename=${printPreview.first}")...