This just uses the cake qdisc as a replacement for both htb as shaper and fq_codel as leaf qdisc.
It just does not come any simpler than this, in other words it truely is a "piece of cake".
This script requires that cake is selected as qdisc, and forces its usage.
See: http://www.bufferbloat.net/projects/codel/wiki/Cake for more information