code: public RolloverDescription initialize(
      final String file, final boolean append) {
      String newActiveFile = file;
      explicitActiveFile = false;
  
      if (activeFileName != null) {
        explicitActiveFile = true;
        newActiveFile = activeFileName;
      }
  
      if (file != null) {
        explicitActiveFile = true;
        newActiveFile = file;
      }
  
      if (!explicitActiveFile) {
        StringBuffer buf = new StringBuffer();
        formatFileName(new Integer(minIndex), buf);
        newActiveFile = buf.toString();
      }
  
      return new RolloverDescriptionImpl(newActiveFile, append, null, null);
    }
docs: {@inheritDoc}