presto-thrift-api/src/main/java/io/prestosql/plugin/thrift/api/valuesets/PrestoThriftRangeValueSet.java/PrestoThriftMarker/toString
class PrestoThriftMarker:        @Override
        public String toString()
        {
            return toStringHelper(this)
                    .add("value", value)
                    .add("bound", bound)
                    .toString();
        }