@Override
    public String toString() {
      StringBuilder builder = new StringBuilder();
      builder.append("file: ").append(file.getPath()).append("; ")
        .append("operation: ");
      if ((eventMask & FILE_TRANSIENT_STATE_CHANGED) != 0) builder.append("TRANSIENT_STATE_CHANGE ");
      if ((eventMask & FILE_CONTENT_CHANGED) != 0) builder.append("CONTENT_CHANGE ");
      if ((eventMask & FILE_REMOVED) != 0) builder.append("REMOVE ");
      if ((eventMask & FILE_ADDED) != 0) builder.append("ADD ");
      return builder.toString().trim();
    }
@Override
    public String toString()