presto-parser/src/main/java/io/prestosql/sql/tree/QuerySpecification.java/QuerySpecification/toString
class QuerySpecification:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("select", select)
                .add("from", from)
                .add("where", where.orElse(null))
                .add("groupBy", groupBy)
                .add("having", having.orElse(null))
                .add("orderBy", orderBy)
                .add("offset", offset.orElse(null))
                .add("limit", limit.orElse(null))
                .toString();
    }