Can't find RecoverabilityAction.Discard

The Custom Recoverability Policy page mentions RecoverabilityAction.Discard(reason) option. But I can’t seem to find it in the NServiceBus assembly? Is it new or deprecated?

New for 7.2: Add discard as an option for custom recoverability policies by danielmarbach · Pull Request #5327 · Particular/NServiceBus · GitHub