Auth_OpenID_ServerError::whichEncoding PHP Method

    function whichEncoding()
    {
        global $_Auth_OpenID_Request_Modes;
        if ($this->hasReturnTo()) {
            if ($this->message->isOpenID2() && strlen($this->encodeToURL()) > Auth_OpenID_OPENID1_URL_LIMIT) {
                return Auth_OpenID_ENCODE_HTML_FORM;
            } else {
                return Auth_OpenID_ENCODE_URL;
            }
        }
        if (!$this->message) {
            return null;
        }
        $mode = $this->message->getArg(Auth_OpenID_OPENID_NS, 'mode');
        if ($mode) {
            if (!in_array($mode, $_Auth_OpenID_Request_Modes)) {
                return Auth_OpenID_ENCODE_KVFORM;
            }
        }
        return null;
    }

 function test_noMessage()
 {
     $e = new Auth_OpenID_ServerError();
     $this->assertFalse($e->hasReturnTo());
     $this->assertEquals($e->whichEncoding(), null);
     $this->assertEquals($e->getReturnTo(), null);
 }