presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/model/Row.java/Row/toString
class Row:    @Override
    public String toString()
    {
        if (fields.isEmpty()) {
            return "()";
        }
        else {
            StringBuilder builder = new StringBuilder("(");
            for (Field f : fields) {
                builder.append(f).append(",");
            }
            builder.deleteCharAt(builder.length() - 1);
            return builder.append(')').toString();
        }
    }