Embedding Camunda in other platform. How do I pass a java object during fetchAndLock to retrieve it back in delegate class?

Embedding Camunda in other platform. How do I pass a java object during fetchAndLock so that I can retrieve it back in delegate class? This java object represents some data about the platform’s logged in user. I need it back in delegate class so i can invoke some other call to same platform. Also note that 2 separate usersessions logged in to same platform using same Camunda engine will have separate java object referred above. Also such object is only in the memory and cannot be retrieved from db in delegate. So can variables be used to push such user context java object to be retreived in delegate? And if so can you let me know the pseudo code for it?