code: private static<V> TreeMap<String, V> getValuesMap (String prefix, ParamReader<V> reader) {
  
          TreeMap<String, V> map = null;
  
          Iterator iter = config().getKeys(prefix);
          while(iter.hasNext()){
              String key = iter.next().toString();
  
              if (map == null) {
                  map = new TreeMap(keysComparator); // make sure that all keys are inserted by their configured order
              }
  
              map.put(key, reader.readValue(key));
          }
  
          return map;
      }
docs: return a map with all keys and values where the entries are sorted by the configured order