docs: public static TopologyAPI.Config.Builder getConfigBuilder(Config config) {
      TopologyAPI.Config.Builder cBldr = TopologyAPI.Config.newBuilder();
      Set<String> apiVars = config.getApiVars();
      for (String key : config.keySet()) {
        if (key == null) {
          LOG.warning("ignore: null config key found");
          continue;
        }
        Object value = config.get(key);
        if (value == null) {
          LOG.warning("ignore: config key " + key + " has null value");
          continue;
        }
        TopologyAPI.Config.KeyValue.Builder b = TopologyAPI.Config.KeyValue.newBuilder();
        b.setKey(key);
        if (apiVars.contains(key)) {
          b.setType(TopologyAPI.ConfigValueType.STRING_VALUE);
          b.setValue(value.toString());
        } else {
          b.setType(TopologyAPI.ConfigValueType.JAVA_SERIALIZED_VALUE);
          b.setSerializedValue(ByteString.copyFrom(serialize(value)));
        }
        cBldr.addKvs(b);
      }
  
      return cBldr;
    }