docs: public Parameters copyMergingIntoCurrentNamespace(final Parameters paramsToAdd) {
      // we use the immutable map builder even though it requires tracking seen
      // items separately to maintain determinism
      final ImmutableMap.Builder<String, String> newParamsMap = ImmutableMap.builder();
      final Set<String> seen = Sets.newHashSet();
  
      newParamsMap.putAll(paramsToAdd.params);
      seen.addAll(paramsToAdd.params.keySet());
      newParamsMap.putAll(Maps.filterKeys(params, not(in(seen))));
      return new Parameters(newParamsMap.build(), namespace);
    }