$ user.fork(); forked.detach()

user.id=1e58e5c6-f976-4fbc-9e10-9b32e6a3c5a6
forked.id=aecafba1-82c8-48e1-b7e1-61deee9b0422
forked.parent_session_ids=['1e58e5c6-f976-4fbc-9e10-9b32e6a3c5a6']
forked.lineage_operator=Session.fork
detached.id=ab304c59-fc2a-4fe7-8072-6717fa942193
detached.parent_session_ids=[]
detached.lineage_operator=Session.detach