title: Runkit can't redefine static method
body: <p>I have this class</p>
  
  <pre><code>class DateTimeHelper
  {
      public static function getDateTimeNow()
      {
          return new \DateTime('now');
      }
  }
  </code></pre>
  
  <p>And I want in tests redefine output to date that I want:</p>
  
  <p>So I do:</p>
  
  <pre><code>    $r = runkit_method_redefine(
          DateTimeHelper::class,
          'getDateTimeNow',
          '',
          'return new \DateTime(\'2016-01-01\');',
          (RUNKIT_ACC_PUBLIC | RUNKIT_ACC_STATIC)
      );
  
      var_dump($r);
      var_dump(DateTimeHelper::getDateTimeNow());
  </code></pre>
  
  <p>But runkit always returns false. So method is not redefined I get current datetime and can't get more info about what is wrong.</p>
  
  <p>Is there way to to get more information wht is wrong or am I doing something wrong?</p>