TODO This is a utility function to compute to be removed and to be added substructures in resource configurations.

NotFoundError represents when a StateRefreshFunc returns a nil result during a StateChangeConf waiter method and that StateChangeConf is configured for specific targets.

StateChangeConf is the configuration struct used for `WaitForState`.

TimeoutError is returned when WaitForState times out.

UnexpectedStateError is returned when Refresh returns a state that's neither in Target nor Pending.

StateRefreshFunc is a function type used for StateChangeConf that is responsible for refreshing the item being watched for a state change.