@Override
    public byte[] putIfAbsent(final Bytes key,
                              final byte[] valueAndTimestamp) {
        final byte[] previous = wrapped().putIfAbsent(key, valueAndTimestamp);
        if (previous == null) {
            // then it was absent
            log(key, rawValue(valueAndTimestamp), valueAndTimestamp == null ? context.timestamp() : timestamp(valueAndTimestamp));
        }
        return previous;
    }
@Test
    public void shouldWriteToInnerOnPutIfAbsentNoPreviousValue() {
        store.putIfAbsent(hi, rawThere);
        assertThat(root.get(hi), equalTo(rawThere));
    }