@Override public InputStream nextElement() {
                for (int i = 0; i <      idSize; i++) buffer[  idIndex + i] = (byte) ('a' + (random.nextInt(26)));
                for (int i = 0; i < payloadSize; i++) buffer[dataIndex + i] = (byte) ('a' + (random.nextInt(26)));
                return new ByteArrayInputStream(buffer);
            }
Creates an input stream that spits out random documents (id and data) for one minute.
vespa-feed-client-cli/src/main/java/ai/vespa/feed/client/impl/CliClient.java