title: PHPUnit: What happens to variables not addressed by the tearDown() method?
body: <p>I would like to know whether the setting <code>null</code> to variables in the <code>tearDown</code> methods within <code>PHPUnit_Framework_TestCase</code> and children is <strong>a mere formality</strong> or serves some actual purpose.</p>
  
  <p>Example:</p>
  
  <pre><code>protected function tearDown(){
    $this-&gt;someUsedVariable=null;
  }
  </code></pre>
  
  <p>P.S.: I mean, don't used variables <strong>get destroyed anyway</strong> by the end of the script?</p>