byte[] getExpectedData(MockId id, boolean wantPut) {
    Offset offset = getExpectedValue(id, wantPut).getOffset();
    return logOrder.get(offset).getSecond().buffer;
  }
Gets the data that is expected to obtained from the {@link Log}.
@param id the {@link MockId} whose value is required.
@param wantPut {@code true} if the {@link IndexValue} of the PUT entry is required.
@return the value that is expected to obtained from the {@link PersistentIndex}
ambry-store/src/test/java/com/github/ambry/store/CuratedLogIndexState.java