code: TemplateTypeMap copyFilledWithValues(ImmutableList<JSType> additionalValues) {
      ImmutableList<JSType> finalValues =
          resizedToMatchKeys(concatImmutableLists(templateValues, additionalValues));
      return registry.createTemplateTypeMap(templateKeys, finalValues);
    }
docs: Returns a new TemplateTypeMap whose values have been extended with the specified list.