code: function(err){
                  client.del(recommendedZSet, function(err){
                    async.each(scoreMap,
                      function(scorePair, callback){
                        client.zadd(recommendedZSet, scorePair[0], scorePair[1], function(err){
                          callback();
                        });
                      },
                      // after all the additions have been made to the recommended set,
                      function(err){
                        client.del(tempAllLikedSet, function(err){
                          client.zcard(recommendedZSet, function(err, length){
                            client.zremrangebyrank(recommendedZSet, 0, length-config.numOfRecsStore-1, function(err){
                              cb();
                            });
                          });
                        });
                      }
                    );
                  });
                }
docs: using score map which is an array of what the current user would rate all the unrated items, add them to that users sorted recommended set