 		//only care if it is one of our containers
 		guard let from = try? event.json.getString(at:"from"),
 			let ctype = ContainerType.from(imageName:from),
-			let container = containers[ctype] else { return }
+			let container = self.containers[ctype] else { return }
 		switch event.eventType {
 			case .die:
 				os_log("warning: container died: %{public}@", log:.docker, from)

}

//MARK: - Private Methods
fileprivate extension DockerManager {
	/// Validates the version parameter meets requirements.
	///
	/// - parameter version: the version information to check

	/// - returns: a signal producer with no value
	public func perform(operation: DockerContainerOperation, on inContainers: [DockerContainer]? = nil) -> SignalProducer<(), Rc2Error>
	{
		var selectedContainers = self.containers!
		if inContainers != nil {
			selectedContainers = inContainers!
		}
