code: def get_activities_by_objective_bank(self, objective_bank_id):
          
          # Implemented from template for
          # osid.resource.ResourceBinSession.get_resources_by_bin
          mgr = self._get_provider_manager('LEARNING', local=True)
          lookup_session = mgr.get_activity_lookup_session_for_objective_bank(objective_bank_id, proxy=self._proxy)
          lookup_session.use_isolated_objective_bank_view()
          return lookup_session.get_activities()
docs: Gets the list of ``Activities`` associated with an ``ObjectiveBank``.
  
          arg:    objective_bank_id (osid.id.Id): ``Id`` of the
                  ``ObjectiveBank``
          return: (osid.learning.ActivityList) - list of related
                  activities
          raise:  NotFound - ``objective_bank_id`` is not found
          raise:  NullArgument - ``objective_bank_id`` is ``null``
          raise:  OperationFailed - unable to complete request
          raise:  PermissionDenied - authorization failure
          *compliance: mandatory -- This method must be implemented.*