title: Is method signature in PHP a MUST or SHOULD?
body: <p>I mean if it's called with <code>$request</code> which is not instance of <code>sfWebRequest</code> ,will it be fatal,or just a warning?</p>
  
  <pre><code>class jobActions extends sfActions
  {
    public function executeIndex(sfWebRequest $request)
    {
      $this-&gt;jobeet_job_list = Doctrine::getTable('JobeetJob')
        -&gt;createQuery('a')
        -&gt;execute();
    }
  
    // ...
  }
  </code></pre>