@Override
        public ByteBuffer create(final int depth, final ByteBuffer parentRowKey, final StoredValues storedValues) {
            final long timeMs = storedValueKeyFactory.getTimeMs(storedValues);
            final ByteBuffer byteBuffer = byteBufferFactory.acquire(KEY_LENGTH);
            byteBuffer.putLong(timeMs);
            byteBuffer.putLong(uniqueIdProvider.getUniqueId());
            return byteBuffer.flip();
        }
Creates flat time based unique key. <TIME_MS><UNIQUE_ID>
stroom-query/stroom-query-common/src/main/java/stroom/query/common/v2/LmdbRowKeyFactoryFactory.java