private void awaitFuture(CompletableFuture<Boolean> renderTask) {
        try {
            renderTask.get();
        } catch (InterruptedException | ExecutionException e) {
            throw new ApplicationException(e);
        }
    }
Processes the given request with the given chain, and returns the response.

@param chain the specification of the chain to execute
@param request the request to process
@return a response
application/src/main/java/com/yahoo/application/container/ProcessingBase.java