code: def get_composition_ids_by_repositories(self, repository_ids):
          
          # Implemented from template for
          # osid.resource.ResourceBinSession.get_resource_ids_by_bins
          id_list = []
          for composition in self.get_compositions_by_repositories(repository_ids):
              id_list.append(composition.get_id())
          return IdList(id_list)
docs: Gets the list of ``Composition``  ``Ids`` corresponding to a list of ``Repository`` objects.
  
          arg:    repository_ids (osid.id.IdList): list of repository
                  ``Ids``
          return: (osid.id.IdList) - list of composition ``Ids``
          raise:  NullArgument - ``repository_ids`` is ``null``
          raise:  OperationFailed - unable to complete request
          raise:  PermissionDenied - authorization failure
          *compliance: mandatory -- This method must be implemented.*