title: Mock a method in the same class being tested
body: <p>I want to mock a method in the same class that I am testing.</p>
  
  <pre><code>ClassA {
     function hardToTest($arg) {
        // difficult to test code
     }
  
     function underTest() {
        return $this-&gt;hardToTest('foo');
     }
  }
  </code></pre>
  
  <p>I was thinking that I could use reflection to do this, but maybe it is just a sign that I should move <code>hardToTest</code> into another object.</p>