presto-parser/src/main/java/io/prestosql/sql/tree/OrderBy.java/OrderBy/equals
class OrderBy:    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) {
            return true;
        }
        if ((obj == null) || (getClass() != obj.getClass())) {
            return false;
        }
        OrderBy o = (OrderBy) obj;
        return Objects.equals(sortItems, o.sortItems);
    }