@Override
    public String toString() {
      StringBuilder sb = new StringBuilder();
      sb.append("CompactionDetails:")
          .append(compactionDetails.toString())
          .append("\n")
          .append("CopyStartTime:")
          .append(copyStartTime)
          .append("\n")
          .append("CommitStartTime:")
          .append(commitStartTime)
          .append("\n")
          .append("CleanupStartTime:")
          .append(cleanupStartTime)
          .append("\n")
          .append("CycleEndTime:")
          .append(cycleEndTime)
          .append("\n");
      if (safeToken != null) {
        sb.append("SafeToken:").append(safeToken.toString()).append("\n");
      }
      return sb.toString();
    }
@return serialized version of the {@link CycleLog}.
ambry-store/src/main/java/com/github/ambry/store/CompactionLog.java