private boolean isFailed() {
      return exception != null;
    }
This class provides the ability to serialize the given SchemaRegionPlan into binary data, which
is compatible with that of PhysicalPlan in 0.14 snapshot versions.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/logfile/visitor/SchemaRegionPlanSerializer.java