code: private void readConfigFile() {
      File configFile = new File(CONFIG_FILE_PATH);
      /* config file is not there -> create config file with default */
      if (!configFile.exists()) {
        resetConfigToDefault();
      }
  
      try {
        PropertiesConfiguration conf = new PropertiesConfiguration(CONFIG_FILE_PATH);
        chemistry = conf.getString(CHEMISTRY_PLUGIN);
      } catch (ConfigurationException e) {
        resetConfigToDefault();
        e.printStackTrace();
      }
    }
docs: method to read the configuration file