https://github.com/JSQLParser/JSqlParser/blob/8e651ff232171eb31ac3eb0aad498cd210a7ef23/src/main/java/net/sf/jsqlparser/expression/PreferringClause.java#L17-L18 There are no getters for the `preferring` `Expression`, and the `partitionBy` `PartitionByClause`. This means that you can't tree walk into the Expression / PartitionByClause contained