obr has optional dependency on org.osgi.service.obr pkg

[Sanjeeb Sahoo]

org.apache.felix.bundlerepository-1.6.2.jar has an optional 
Import-Package obr API as shown below:

org.osgi.service.obr;resolution:=optional;version="[1.0,2)"
Is this correct or should this be a mandatory dependency?

Thanks,
Sahoo