Delete `labels` from the store, which involves deleting two
        records for each :class:`Label`.

        :rtype: None
        :raises: :exc:`KeyError` if any of the `labels` could not be found.

def delete(self, *labels):
        '''Delete `labels` from the store, which involves deleting two
        records for each :class:`Label`.

        :rtype: None
        :raises: :exc:`KeyError` if any of the `labels` could not be found.

        '''
        deletes = []
        for label in labels:
            k1, k2 = self._keys_from_label(label)
            deletes.append(k1)
            deletes.append(k2)
        self.kvl.delete(self.TABLE, *deletes)