/**
  * @covers WPSEO_Frontend::nofollow_link
  */
 public function test_nofollow_link()
 {
     $input = '<a href="#">A link</a>';
     $expected = str_replace('<a ', '<a rel="nofollow" ', $input);
     $this->assertEquals($expected, self::$class_instance->nofollow_link($input));
 }