Flow :
Triggerable Task0(Async Triggerable Task) ----- Parallel Gateway ----> Concurrent Future Delegate (Asyn Task 1) , Concurrent Future Delegate (Async Task2)
Task 0 - It is a triggerable task , Call Rest Apis(Spring Reactive) and then runtimeservice.trigger(execution, variables) is invoked once rest API invocation is completed.
Task 0 invokes parallel gateway which then invokes Task 1 and Task2 parallely .
Optimistic Lock Exception occurs when runtimeservice.trigger(execution, variables) in trigger method (Task0)