Ymka2007 , %Library.Persistent наследуется от %SwizzleObject... А тот в свою очередь от %RegisteredObject... Так вот у этого самого %RegisteredObject есть метод %ConstructClone.

Я в аглицком не очень... Но возможно это то, что нужно.

автор• method %ConstructClone(deep As %Boolean = 0, ByRef cloned As %String, location As %String) as %RegisteredObject
Clone the current object to a new object. If deep is 1 then this does a deep copy which will also copy any subobjects and if deep is 0 then it will create another reference to any subobjects and increment the reference count appropriately. It returns the new cloned object.
Note that even if deep=0 when you clone a parent object in a parent child relationship or a one object of a one to many relationship then it will construct clones of all the child/many objects. This is because a child/many object can only point at a single parent and so if we did not create a clone of these then you would have a relationship with zero items in it. If you really just want to clone the object without these child/many objects then pass deep=-1 to this method.

After the clone is constructed it will call %OnConstructClone(deep,.cloned) if it is defined so that you can perform any additional steps e.g. taking out a lock. This works just the same way as %OnNew() does.

The cloned array is just used internally when doing a deep clone to prevent recursive loops, do not pass anything in at all for this parameter on the initial call. If you write a %OnConstructClone and from here you wish to call %ConstructClone on another object pass in the cloned array, e.g. 'Do oref.%ConstructClone(1,.cloned)' so that it can prevent recursive loops.

The location is used internally to pass the new location for stream objects.