XREADGROUP

The block with subtitle **`Consumer groups in 30 seconds`** takes well more than 30 seconds.
- https://thereadtime.com/ estimates 1 minute 20 seconds of silent reading (1 minute 44 seconds of talk).
- https://flaketools.com/tools/reading-time-calculator estimates almost same as above (1 second less).
- https://niram.org/read/ estimates 1 minute 35 seconds of reading.