title: OData : Why am I getting HTTP 428 (Precondition Required) error while performing an update
body: <p>So here's my code</p>
  
  <pre><code>sap.ui.getCore().getModel("myModel").update("/ZSystemNameSet(mandt='001')", data, null, function(datay, responsey){
              sap.ui.getCore().getModel().refresh();
              MessageToast.show("It worked...!! Data: "+datay+"Response: "+responsey);
          }, function(datax,responsex){
              MessageToast.show("Sorry! Data: "+datax+"Response: "+responsex);
          });
  </code></pre>
  
  <p>Also how do I add the header attributes to the update() call?</p>