Setting a timer within broadcast applyToKeyedState() (feature request)

[James Sandys-Lumsdaine]

Hello,

I know we can’t set a timer in the processBroadcastElement() of the 
KeyedBroadcastProcessFunction as there is no key. 

However, there is a context.applyToKeyedState() method which allows us to 
iterate over the keyed state in the scope of a key. So it is possible to add 
access to the TimerService onto the Context parameter passed into that 
delegate? 

Since the code running in the applyToKeyedState() method is scoped to a key we 
should be able to set up timers for that key too. 

Thanks,

James.