As explained in https://www.rudder-project.org/foswiki/Development/TechniqueBestPractices, the classes should be raised by the use of <b>rudder_common_classes</b>:
<i>
- "rudder_<name of the Technique>_<action>_error" should be raised simultaneously as "rudder_<name of the Technique>_<action>_failed", "rudder_<name of the Technique>_<action>_denied" or "rudder_<name of the Technique>_<action>_timeout".
- The body rudder_common_classes automatically abide by this rule 
</i>