GcGetSubjects returns only the first value of a multi-valued attribute

WsSubjectLookup sl = new WsSubjectLookup();

sl.setSubjectId("myuserid");

GcGetSubjects gs = new GcGetSubjects()

                .addWsSubjectLookup(sl)

                .addSubjectAttributeName("myattribute");

WsGetSubjectsResults results = gs.execute();

WsSubject[] subjects = results.getWsSubjects();

for(String value : subjects[0].getAttributeValues()) {

   // Only the first value of the multi-valued attribute is retrieved

   // I know that the array should have one entry for each different attribute name,

   // but I'm expecting here to have at least a string with a list of a comma separated values,

   // as happen in the Grouper UI admin panel.

}

GcLdapSearchAttribute ls = new GcLdapSearchAttribute()

                .assignLdapName("...")

                .addMatchingAttribute("uid", "myuserid")

                .addReturningAttribute("myattribute");

ls.execute();

ls.retrieveResultAttributeStringList(); // <-- This works!