@Override
  public IDeviceMNode<IMemMNode> getAsDeviceMNode() {
    if (isDevice()) {
      return new DeviceMNodeWrapper<>(this);
    } else {
      throw new UnsupportedOperationException("Wrong node type");
    }
  }
MNodeContainer reference and basic occupation, 8 + 80B. DeviceInfo reference and size.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/mem/mnode/impl/BasicInternalMNode.java