presto-hive/src/main/java/io/prestosql/plugin/hive/SortingFileWriter.java/SortingFileWriter/toString
class SortingFileWriter:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("tempFilePrefix", tempFilePrefix)
                .add("outputWriter", outputWriter)
                .toString();
    }