def METHOD_NAME(self, method_name, *args, **kwargs):
    """trace the execution of the multi command with the given name."""
    method = getattr(self.__wrapped__, method_name)
    with self._span(method_name) as span:
        pre = kwargs.get("key_prefix")
        if span and pre:
            span.set_tag_str(memcached.QUERY, "%s %s" % (method_name, pre))
        if method_name == "get_multi":
            result = method(*args, **kwargs)
            # returns mapping of key -> value if key exists, but does not include a missing key. Empty result = {}
            span.set_metric(
                db.ROWCOUNT, sum(1 for doc in result if doc) if result and isinstance(result, Iterable) else 0
            )
            return result
        else:
            return method(*args, **kwargs)