code: def get_asset_repository_assignment_session(self):
          
          if not self.supports_asset_repository_assignment():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.AssetRepositoryAssignmentSession(runtime=self._runtime)
docs: Gets the session for assigning asset to repository mappings.
  
          return: (osid.repository.AssetRepositoryAssignmentSession) - an
                  ``AssetRepositoryAsignmentSession``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented -
                  ``supports_asset_repository_assignment()`` is ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_asset_repository_assignment()`` is ``true``.*