code: @Override
      public Map<String, String> values() {
          Map<String, String> values = new LinkedHashMap<>();
          for (Row each : delegates) {
              for (Entry<String, String> entry : each.values().entrySet()) {
                  String name = entry.getKey();
                  if (!values.containsKey(name)) {
                      values.put(name, entry.getValue());
                  }
              }
          }
          return values;
      }
docs: Returns values aggregated from all the delegates, without overriding
  values that already exist.
  
  @return The Map of aggregated values