code: public void properties(String line, DispatchCallback callback)
        throws Exception {
      String example = "";
      example += "Usage: properties <properties file>" + SqlLine.getSeparator();
  
      String[] parts = sqlLine.split(line);
      if (parts.length < 2) {
        callback.setToFailure();
        sqlLine.error(example);
        return;
      }
  
      int successes = 0;
  
      for (int i = 1; i < parts.length; i++) {
        Properties props = new Properties();
        props.load(new FileInputStream(parts[i]));
        connect(props, callback);
        if (callback.isSuccess()) {
          successes++;
          String nickname = getProperty(props, "nickname", "ConnectionNickname");
          if (nickname != null) {
            sqlLine.getDatabaseConnection().setNickname(nickname);
          }
        }
      }
  
      if (successes != parts.length - 1) {
        callback.setToFailure();
      } else {
        callback.setToSuccess();
      }
    }
docs: Connects to the database defined in the specified properties file.
  
  @param line Command line
  @param callback Callback for command status
  @throws Exception on error