get_composition_latest returns a COMPOSITION, with just that is not possible to test if the returned object is the latest version of the COMPO.
Same happens on get_composition_at_time and get_composition_at_version operations.
A solution would be to return VERSION<COMPOSITION>, which contains the version uid, and with the first part of the uid we can get the VERSIONED_COMPOSITION with all the versions and check the one we got is the latest.
That can be done if get_versioned_composition returns a VERSIONED_COMPOSITION with the list of version uids inside.
Note: there is a discussion in the SEC slack about having or not a convention to have the complete version id in the COMPOSITION.uid, which makes sense but from memory I don't recall if this is specified anywhere. Need to look for this in the specs to be sure it is not specified.