code: def get_assessments_offered(self):
          
          if self.retrieved:
              raise errors.IllegalState('List has already been retrieved.')
          self.retrieved = True
          return objects.AssessmentOfferedList(self._results, runtime=self._runtime)
docs: Gets the assessment offered list resulting from the search.
  
          return: (osid.assessment.AssessmentOfferedList) - the assessment
                  offered list
          raise:  IllegalState - the assessment offered list has already
                  been retrieved
          *compliance: mandatory -- This method must be implemented.*