added getDomain

@@ -164,13 +164,25 @@ abstract class ImmoScoutAPI extends GuzzleClient
     }
 
     /**
+     * get is24 domain depending on the sandbox.
+     *
+     * @return string base url
+     */
+    public function getDomain()
+    {
+        return $this->isSandbox ? 'sandbox-immobilienscout24.de' : 'immobilienscout24.de';
+    }
+
+    /**
      * get base api url depending on the sandbox.
      *
      * @return string base url
      */
     private function getBaseUrl()
     {
-        return $this->isSandbox ? 'https://rest.sandbox-immobilienscout24.de/restapi/' : 'https://rest.immobilienscout24.de/restapi/';
+        $domain = $this->getDomain();
+
+        return 'https://rest.' . $domain . '/restapi/';
     }
 
     /**