def unassign_comment_from_book(self, comment_id, book_id):
        """Removes a ``Comment`` from a ``Book``.

        arg:    comment_id (osid.id.Id): the ``Id`` of the ``Comment``
        arg:    book_id (osid.id.Id): the ``Id`` of the ``Book``
        raise:  NotFound - ``comment_id`` or ``book_id`` not found or
                ``comment_id`` not assigned to ``book_id``
        raise:  NullArgument - ``comment_id`` or ``book_id`` 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.ResourceBinAssignmentSession.unassign_resource_from_bin
        mgr = self._get_provider_manager('COMMENTING', local=True)
        lookup_session = mgr.get_book_lookup_session(proxy=self._proxy)
        lookup_session.get_book(book_id)  # to raise NotFound
        self._unassign_object_from_catalog(comment_id, book_id)
Removes a ``Comment`` from a ``Book``.

        arg:    comment_id (osid.id.Id): the ``Id`` of the ``Comment``
        arg:    book_id (osid.id.Id): the ``Id`` of the ``Book``
        raise:  NotFound - ``comment_id`` or ``book_id`` not found or
                ``comment_id`` not assigned to ``book_id``
        raise:  NullArgument - ``comment_id`` or ``book_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*