org.osgi.service.blueprint Dependency

[Harald Wellmann]

Looking at the Aries Blog sample sources, I noticed that almost all 
bundles have an

Import-Package: org.osgi.service.blueprint
dependency, but I can see no such import in the Java sources.

Is this really required at runtime?
And if so, what makes the Maven Bundle Plugin include this dependency - 
it doesn't seem to be in the compiled classes, and I can't see an 
explicit configuration for this package.

Regards,
Harald