code: public RolloverDescription initialize(
      final String currentActiveFile, final boolean append) {
      long n = System.currentTimeMillis();
      nextCheck = ((n / 1000) + 1) * 1000;
  
      StringBuffer buf = new StringBuffer();
      formatFileName(new Date(n), buf);
      lastFileName = buf.toString();
  
      //
      //  RollingPolicyBase.activeFileName duplicates RollingFileAppender.file
      //    and should be removed.
      //
      if (activeFileName != null) {
        return new RolloverDescriptionImpl(activeFileName, append, null, null);
      } else if (currentActiveFile != null) {
        return new RolloverDescriptionImpl(
          currentActiveFile, append, null, null);
      } else {
        return new RolloverDescriptionImpl(
          lastFileName.substring(0, lastFileName.length() - suffixLength), append,
          null, null);
      }
    }
docs: {@inheritDoc}