The Object class has the following new attributes:

The InstanceIdentifier attribute contains a value that uniquely identifies this instance of an allocated object. The value is guaranteed to be unique among the set of instantiated objects for an OpenROAD session. It is valid only during the life of this object. When this object is freed, the value is available for reuse.

The InstanceReferences attribute contains the current number of references to this instantiated object. A value of zero represents a permanent object that cannot be freed.