code: @Override
    public  String getIndexName(Event event) {
      String realIndexPrefix = BucketPath.escapeString(event.getIndexPrefix() != null ? event.getIndexPrefix() : indexPrefix, event.getHeaders());
      if(event.getIndexTimestamp() != null){
  
        String indexName = new StringBuilder(realIndexPrefix).append('-')
                .append(event.getIndexTimestamp()).toString();
        if(logger.isDebugEnabled())
          logger.debug("Index Name = " + indexName);
        return indexName;
      }
      else {
        TimestampedEvent timestampedEvent = new TimestampedEvent(event);
        long timestamp = timestampedEvent.getTimestamp();
        String indexName = new StringBuilder(realIndexPrefix).append('-')
                .append(fastDateFormat.format(timestamp)).toString();
        if(logger.isDebugEnabled())
          logger.debug("Index Name = " + indexName);
        return indexName;
      }
    }
docs: Gets the name of the index to use for an index request
  @param event
  Event for which the name of index has to be prepared
  @return index name of the form 'indexPrefix-formattedTimestamp'