@abc.abstractmethod<EOL><INDENT>def get_assessments_offered(self):<DEDENT>
return<EOL>
Gets all ``AssessmentOffered`` elements.

        In plenary mode, the returned list contains all known
        assessments offered or an error results. Otherwise, the returned
        list may contain only those assessments offered that are
        accessible through this session.

        :return: a list of ``AssessmentOffered`` elements
        :rtype: ``osid.assessment.AssessmentOfferedList``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure occurred

        *compliance: mandatory -- This method must be implemented.*