ServiceUserMapped (Apache Sling 9 API)

```
@ProviderType
public interface ServiceUserMapped
```
The ServiceUserMapped is a marker service that can be used to ensure that there is an already registered mapping for a certain service/subService. A service reference targeting a ServiceUserMapped will be satisfied only if ServiceUserMapper.getServiceUserID will resolve the subService to an userID. For example setting the reference target to "(subServiceName=mySubService)" ensures that your component only starts when the subService is available. The subServiceName will not be set for mappings that do not have one, and those can be referenced with a negating target "(!(subServiceName=*))". Trying to reference a sub service from a bundle for which it was not registered for will not work. As the service user mapper implementation is using a fallback, it is usually best to use a reference target that includes both options, the sub service name and the fallback, therefore a target like "(|((subServiceName=mySubService)(!(subServiceName=*))))" should be used.

Fields
Modifier and Type	Field and Description
`static String`	`SUBSERVICENAME` The name of the osgi property holding the sub service name.

Interface ServiceUserMapped