SDIFFSTORE
Syntax
        SDIFFSTORE destination key [key ...]
- Available since:
 - 1.0.0
 - Time complexity:
 - O(N) where N is the total number of elements in all given sets.
 - ACL categories:
 - 
              
                
@write,@set,@slow, 
This command is equal to SDIFF, but instead of returning the resulting set, it
is stored in destination.
If destination already exists, it is overwritten.