catch ratelimit exception but not tested

Xero.php

@@ -2,6 +2,8 @@
 namespace Biukop;
 
 use \XeroPHP\Application\PrivateApplication;
+use \XeroPHP\Remote\Exception\RateLimitExceededException; 
+
 class Xero {
     private $xero;
     private $clientgroup="48646f3d-cf5e-4fea-8c8b-5812bd540e1b";
@@ -70,8 +72,13 @@ class Xero {
     //sync users to wordpress system
     //does not work for too many users or employees
     public function sync_users(){
-        $this->sync_clients();
-        $this->sync_employees();
+        try{
+            $this->sync_clients();
+            $this->sync_employees();
+        }catch(RateLimitExceededException $e){
+            $msg= "Xero API rate limit exceeded, please try again later, existing sync within 600 seconds will by passed automatically\n";
+            $this->logConsole($msg);
+        }
     }
     private  function sync_clients(){
         $contacts = $this->getClients($this->clientgroup);