IndexValue markAsPermanent(StoreKey id, FileSpan fileSpan, long operationTimeMs) throws StoreException {
    return markAsPermanent(id, fileSpan, null, operationTimeMs, MessageInfo.LIFE_VERSION_FROM_FRONTEND);
  }
Marks a blob as permanent
@param id the {@link StoreKey} of the blob
@param fileSpan the file span represented by this entry in the log
@param operationTimeMs the time of the update operation
@return the {@link IndexValue} of the ttl update record
@throws StoreException if there is any problem writing the index record
ambry-store/src/main/java/com/github/ambry/store/PersistentIndex.java