@Override
    protected IrRowPattern visitIrLabel(IrLabel node, Boolean inExclusion) {
      return node;
    }
Optimize row pattern: - remove nested exclusions - flatten alternations and concatenations -
remove redundant empty pattern
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/rowpattern/IrRowPatternFlattener.java