void close() {
        rpcDownloadExecutor.shutdownNow();
        try {
            rpcDownloadExecutor.awaitTermination(10, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
An RPC server that handles file distribution requests.

@author hmusum
config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileDistributionRpcServer.java