In reply to cgales:
You are right, this is the classical way.
But in the case you need to implement a coverage driven stimulation (Coverage Driven Verification), there is a feedback loop where you will tune the sequences to hit parts of the covergroup that have not been covered yet.
The idea of CDV is to orientate the stimulation to get a better efficiency (simulation time vs coverage increase rate), and not hit twice items that have already been covered.