code: private static GraphicalModelProto.MetaData.Builder getProtoMetaDataBuilder(Map<String, String> metaData) {
      GraphicalModelProto.MetaData.Builder builder = GraphicalModelProto.MetaData.newBuilder();
      for (String key : metaData.keySet()) {
        builder.addKey(key);
        builder.addValue(metaData.get(key));
      }
      return builder;
    }
docs: //////////////////////////////////////////////////////////////////////////