Gets an existing PFItemSubscription for the given user or return a new persisted one
if one didn't already exist.
This method uses process level locking to ensure the subscription is updated in an atomic manner.
Avoid calling this method from another process (e.g. TimerJobs).
Namespace:Packflow.Core Assembly:
MicaSystems.Packflow.Core (in MicaSystems.Packflow.Core.dll) Version: 1.0.0.0 (3.2.0.306)