public static IrRowPattern optimize(IrRowPattern node) {
    return new Visitor().process(node);
  }
Remove empty pattern from pattern alternation and replace it with quantification of a
neighbouring term.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/rowpattern/IrPatternAlternationOptimizer.java