String componentProject = components.get(0);
ProjectId project = !Strings.isNullOrEmpty(componentProject) ? new ProjectId(componentProject) : null;
String serviceComponent = components.get(1);
ServiceType serviceType = !Strings.isNullOrEmpty(serviceComponent) ? new ServiceType(serviceComponent) : null;
ItemType itemType = new ItemType(components.get(2));
ManagedItemId itemId = new ManagedItemId(Joiner.on("/").join(components.subList(3, components.size())));
return new PlatformLayerKey(hostKey, project, serviceType, itemType, itemId);