Emitted when a ModelReference's value is explicitly cleared.
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.
The first previous value (if there were multiple) of the reference.
The previous values of the reference.
The underlying reference that was cleared.