@Override
    protected IrRowPattern visitIrExclusion(IrExclusion node, Void context) {
      IrRowPattern child = process(node.getPattern());

      return new IrExclusion(child);
    }
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