docs: def set_assessment(self, assessment_id=None):
          """Sets the assessment.
  
          arg:    assessmentId (osid.id.Id): the new assessment
          raise:  INVALID_ARGUMENT - assessmentId is invalid
          raise:  NoAccess - assessmentId cannot be modified
          raise:  NullArgument - assessmentId is null
          compliance: mandatory - This method must be implemented.
  
          """
          if assessment_id is None:
              raise NullArgument()
          metadata = Metadata(**settings.METADATA['assessment_id'])
          if metadata.is_read_only():
              raise NoAccess()
          if self._is_valid_input(assessment_id, metadata, array=False):
              self._my_map['assessmentId'] = str(assessment_id)
          else:
              raise InvalidArgument