CodeIgniter单元测试框架无法在包含句点的字符串上断言

Question

I have the following in CodeIgniter:

class Foo extends CI_Controller
{  
    public function __construct()
    {  
         parent::__construct();  
         $this->load->library('unit_test');
    }  
    public function test() 
    {  
        $ip = '1.2.3.4';  
        $this->unit->run($ip,'1.2.3.4');
    }  
}

The above test fails. Why does the assert equals fail in this unit test? If I pass in a String with no periods . it asserts correctly.

UPDATE

i have just tested it and the result is a pass

echo $this->unit->report();

returns a status of failed.