Which command do you use to add a value to a Redis stream named mystream?
XADD mystream * sensor-id 1234 temperature 9.8 1518951480106-0
UPDATE mystream * sensor-id 1234 temperature 19.8 1518951480106-3
INSERT mystream * sensor-d 1234 temperature 19.8 15181480106-2
ADD mystream * sensor-id 1234 temperature 19.8 1518951480106-1