Gets the list of ``Comment Ids`` corresponding to a list of ``Book`` objects.

        arg:    book_ids (osid.id.IdList): list of book ``Ids``
        return: (osid.id.IdList) - list of comment ``Ids``
        raise:  NullArgument - ``book_ids`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*

def get_comment_ids_by_books(self, book_ids):
        """Gets the list of ``Comment Ids`` corresponding to a list of ``Book`` objects.

        arg:    book_ids (osid.id.IdList): list of book ``Ids``
        return: (osid.id.IdList) - list of comment ``Ids``
        raise:  NullArgument - ``book_ids`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*

        """
        # Implemented from template for
        # osid.resource.ResourceBinSession.get_resource_ids_by_bins
        id_list = []
        for comment in self.get_comments_by_books(book_ids):
            id_list.append(comment.get_id())
        return IdList(id_list)