Override an event's param array? I'm having problems setting up an event. It gets triggered and I can access the event's params array, but I can't override the value like I can with Craft's default events.

MyPlugin_myServiceService.php

public function setTest()
{
    $test = true;

    $event = new Event($this, array(
        'test' =&gt; $test
    ));

    $this-&gt;onAfterSetTest($event);

    return $test;
}

public function onAfterSetTest(Event $event)
{
    $this-&gt;raiseEvent('onAfterSetTest', $event);
}


MyOtherPluginPlugin.php

craft()-&gt;on('myPlugin_myService.afterSetTest', function(Event $event)
{  
    $event-&gt;params['test'] = false;
});


Not sure what I'm doing wrong but 
craft()-&gt;myPlugin_myService-&gt;setTest() returns true.
It looks like it doesn't updated the variables passed to the event directly (referenced) and you have to access the value from the $event object.

public function setTest()
{
    // ...

    $test = $event-&gt;params['test']

    return $test;
}