def similar_items(self, key, replaces):
        """
        Returns a list of (key, value) tuples for all variants of ``key``
        in this DAWG according to ``replaces``.

        ``replaces`` is an object obtained from
        ``DAWG.compile_replaces(mapping)`` where mapping is a dict
        that maps single-char unicode sitrings to another single-char
        unicode strings.
        """
        return self._similar_items("", key, self.dct.ROOT, replaces)