code: public List<Long> getOffsets(OffsetRequest offsetRequest) {
          ILog log = getLog(offsetRequest.topic, offsetRequest.partition);
          if (log != null) {
              return log.getOffsetsBefore(offsetRequest);
          }
          return ILog.EMPTY_OFFSETS;
      }
docs: read offsets before given time
  
  @param offsetRequest the offset request
  @return offsets before given time