presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/index/Indexer.java/Indexer/toString
class Indexer:        @Override
        public String toString()
        {
            return toStringHelper(this)
                    .add("row", new String(row.array(), UTF_8))
                    .add("family", new String(row.array(), UTF_8))
                    .add("visibility", visibility.toString())
                    .toString();
        }