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