Partitioned policy when field not set in key

Partitioned policy is working fine, my requirement is that provided the rate limiting is partitioned in policy but in key I do not mention any rate limit(That is I have not added the “rate”, “per” fields in the key and used the gateway api to set the key).

When I tried, it was not enforcing any kind of rate limiting(nothing is actually mentioned in key but there is something in policy which is not being used due to the partition). I need to use the rate limit mentioned in policy if nothing is specified in the key. How can I do it in Tyk?