Working on issues 2000, and 2001, I am adding more and more classes related to ParameterDriver.
In the develop branch, there are three classes ParameterDriver, ParameterDriversList, and ParameterDriversProvider in the org.orekit.utils package. I have already added ParameterDriversSequence and ParameterDriversSequenceBuilder in the issue-2001 branch, and will soon add field versions too.
What about creating a drivers sub-package beneath org.orekit.utils and moving all the existing and new classes there?