code: public Properties loadPropertiesForSubGroup(ConfigurationManager configurationManager, String handlerPrefix, String groupName) {
          PropertyOperations handlerProps = properties(loadProperties(configurationManager, handlerPrefix));
  
          PropertyOperations defaultProps = handlerProps.filterByAndRemoveKeyPrefix(ChorusConstants.DEFAULT_PROPERTIES_GROUP + ".");
          PropertyOperations configProps = handlerProps.filterByAndRemoveKeyPrefix(groupName + ".");
  
          PropertyOperations merged = defaultProps.merge(configProps);
          return merged.loadProperties();
      }
docs: Get properties for a specific config, for a handler which maintains properties grouped by configNames
  
  Defaults may also be provided in a special default configName, defaults provide base values which may be overridden
  by those set at configName level.
  
  myHandler.config1.property1=val
  myHandler.config1.property2=val
  
  myHandler.config2.property1=val
  myHandler.config2.property2=val
  
  myHandler.default.property1=val