code: protected void fromFlatMap(Map<String, String> map) {
  
      for (Entry<String, String> entry : map.entrySet()) {
        SimpleConfigProperties child;
        child = (SimpleConfigProperties) getChild(entry.getKey(), true);
        child.value = entry.getValue();
      }
    }
docs: @see SimpleConfigProperties#ofFlatMap(String, Map)
  
  @param map the flat {@link Map} of the configuration values.