Handle 2 client

public interface MyEndpoint {
    @GET
    @Path("/my-resource")
    CompletionStage<Response> getMyResource(@QueryParam("param1") String param1,
                                            @QueryParam("param2") String param2);
}

MyEndpoint endpointWithHeader = RestClientBuilder.newBuilder()
        .baseUri("http://example.com")
        .build(MyEndpoint.class);

MyEndpoint endpointWithoutHeader = RestClientBuilder.newBuilder()
        .baseUri("http://example.com")
        .build(MyEndpoint.class);

String missingHeader = "value-from-mobile-app";

BiFunction<Response, Throwable, CompletionStage<Response>> handleStatus = (response, throwable) -> {
    if (response != null && response.getStatus() == 409) {
        MultivaluedMap<String, Object> headers = response.getHeaders();
        if (headers.containsKey("Missing-Header")) {
            headers.add("pin", missingHeader);
            // Call the endpoint again with the missing header using the endpointWithHeader client
            return endpointWithHeader.getMyResource("value1", "value2", missingHeader);
        }
    }
    // Handle other response codes here using the endpointWithoutHeader client
    return CompletableFuture.completedFuture(response);
};

CompletionStage<Response> responseStage = endpointWithoutHeader.getMyResource("value1", "value2");
responseStage.thenCompose(handleStatus)
        .thenApply(response -> {
            if (response.getStatus() == 200) {
                return response.readEntity(MyResource.class);
            } else {
                throw new MyException("Failed to get resource");
            }
        });