code: @Override
      public LogRepositoryBrowser findByMillis(long timestamp) {
          File[] files = listFiles(instanceFilter);
          if (files == null) {
              return null;
          }
  
          File result = null;
          long max = Long.MIN_VALUE;
          for (File file : files) {
              long time = parseTimeStamp(file.getName());
              // Select file with a maximum time stamp which is smaller than 'timestamp'.
              if (max < time && (timestamp < 0 || time <= timestamp)) {
                  max = time;
                  result = file;
              }
          }
  
          // If all files has timestamp bigger than 'timestamp' return null.
          if (result == null) {
              return null;
          } else {
              return new LogRepositoryBrowserImpl(result, new String[] { result.getName() });
          }
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.ws.logging.hpel.LogInstanceBrowser#findByMillis(long)