/**
  * Test whether sandbox custom error handler intercepts errors
  */
 public function testCustomErrorHandler()
 {
     $this->setExpectedException('Exception');
     $this->sandbox->set_error_handler(function ($errno, $errstr) {
         throw new \Exception($errstr);
     });
     $this->sandbox->execute(function () {
         $a[1];
     });
 }