presto-parser/src/main/java/io/prestosql/sql/tree/SortItem.java/SortItem/toString
class SortItem:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("sortKey", sortKey)
                .add("ordering", ordering)
                .add("nullOrdering", nullOrdering)
                .toString();
    }