yii\authclient\OpenId::getReturnUrl PHP Method

    public function getReturnUrl()
    {
        if ($this->_returnUrl === null) {
            $this->_returnUrl = $this->defaultReturnUrl();
        }
        return $this->_returnUrl;
    }

 /**
  * @depends testSetGet
  */
 public function testGetDefaults()
 {
     $client = new OpenId();
     $this->assertNotEmpty($client->getTrustRoot(), 'Unable to get default trust root!');
     $this->assertNotEmpty($client->getReturnUrl(), 'Unable to get default return URL!');
 }