docs: public static JavaRDD<List<Writable>> zeromeanUnitVariance(Schema schema, JavaRDD<List<Writable>> data,
                      List<String> skipColumns) {
          DataRowsFacade frame = DataFrames.toDataFrame(schema, data);
          return DataFrames.toRecords(zeromeanUnitVariance(frame, skipColumns)).getSecond();
      }