whileSubscribedPlugin
Create a new plugin that invokes block each time the subscriber count reaches minSubscriptions. Nothing is invoked when more subscribers than minSubscriptions appear, however, the block will be invoked again if the subscriber count drops below minSubscriptions and then reaches the new value again. The block will be canceled when the subscription count drops below minSubscriptions.
You can safely suspend inside block as it's invoked asynchronously, but be aware that jobs launched inside block will be launched in the PipelineContext of the store, not the subscriber scope
There is no guarantee that this will be invoked when a new subscriber appears It may be so that a second subscriber appears before the first one disappears (due to the parallel nature of coroutines). In that case, the block will continue instead of being canceled and relaunched.
If you want to launch jobs in the scope of the block, use kotlinx.coroutines.coroutineScope.