The number of models that must sync up to the server.
The name of the event that was fired. This is commonly used to filter when using the ConvergenceEventEmitter.events stream.
Note that the name is only guaranteed to be unique within the class / subsystem that is firing it. Names might be reused across classes and subsystems.
Emitted when as offline synchronization progresses. It informs the consumer as to how many models still need to sync to the server.