 class="identifier">employee_class</span> <span class="special">:</span> <span class="identifier">annotate_position</span> <span class="special">{};</span>
</pre>
<p>
        The code above tells X3 to check the rule class if it has an <code class="computeroutput"><span class="identifier">on_success</span></code> or <code class="computeroutput"><span class="identifier">on_error</span></code>
        member functions and appropriately calls them on such events.
      </p>
<a name="__tutorial_with_directive__