code: public Properties toAllProperties() {
      Properties allProp = new Properties();
      // import local properties
      allProp.putAll(toProperties());
  
      // import parent properties
      if (_parent != null) {
        allProp.putAll(_parent.toProperties());
      }
  
      return allProp;
    }
docs: Returns a java.util.Properties file populated with both current and parent properties.