Ephemeris propagator uses setAttitudeProvider to override stored attitude
The Ephemeris propagator loads both states (ephemeris and others) and attitude and returns a list of state objects. However there are many workflows where ephemeris is provided but attitude is not, or where attitude is to be overridden for the same base ephemeris. Having the Ephemeris propagator honor the setAttitudeProvider property will allow users to interact with the attitude of the Ephemeris propagator in the same way they do with all other objects.
(from redmine: issue id 179, created on 2014-10-02, closed on 2015-01-12)