ZDIFF
Syntax
        ZDIFF numkeys key [key ...] [WITHSCORES]
- Available since:
 - 6.2.0
 - Time complexity:
 - O(L + (N-K)log(N)) worst case where L is the total number of elements in all the sets, N is the size of the first set, and K is the size of the result set.
 - ACL categories:
 - 
              
                
@read,@sortedset,@slow, 
This command is similar to ZDIFFSTORE, but instead of storing the resulting
sorted set, it is returned to the client.
Examples
RESP2/RESP3 Reply
- Array reply: the result of the difference including, optionally, scores when the WITHSCORES option is used.