@Override
    public Void visitSchemaRegionPlan(ISchemaRegionPlan plan, StringBuilder stringBuilder) {
      throw new UnsupportedOperationException(
          String.format("%s plan doesn't support serialization.", plan.getPlanType().name()));
    }
This class provides the ability to serialize the given SchemaRegionPlan into binary data as txt
format, which is used for MLogParser.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/logfile/visitor/SchemaRegionPlanTxtSerializer.java