add subscription to existing crossbar session

#1

what is a way to add subscription to a session,
INFO:app:Session (4772300362892170) joined router <sl4xbarwws01.dvms.local> on realm with authrole and authid
DEBUG:app:Event emitted to 0 listeners

basically what I want is adding listeners to the session so that they can use existing session 4772300362892170

DEBUG:app:Adding listener <bound method System.process_heartbeat of <dvmt_event_processor.systems.System object at 0x10b04aa58>> for event
DEBUG:app:Adding listener <bound method System.process_eventstream of <dvmt_event_processor.systems.System object at 0x10b04aa58>> for event
DEBUG:app:Adding listener <function DvmtApp.add_subscription..on_connect at 0x10b098d90> for event
DEBUG:app:Adding listener <function DvmtApp.add_subscription..on_connect at 0x10b098e18>
for event

I know my question is not very clear but I am newish to the crossbar and this job, so please ask away any questions that you may have.