code: @Override
      public File findNext(File current, long timelimit) {
          File[] files = listFiles(filter);
          File result = null;
  
          long min = Long.MAX_VALUE;
          long cur = current == null ? Long.MIN_VALUE : getLogFileTimestamp(current);
          for (File file : files) {
              long time = getLogFileTimestamp(file);
              // Select file with a smallest time stamp bigger than time stamp of the 'current' file.
              if (cur < time && time < min) {
                  min = time;
                  result = file;
              }
          }
          // return 'null' if found file has time stamp outside of the time limit.
          return timelimit > 0 && timelimit < min ? null : result;
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.ws.logging.hpel.LogFileBrowser#findNext(java.io.File, long)