title: Sencha saving to localstorage warning
body: <p>I am getting a warning when saving data to local storage.Saving is working fine for me.but</p>
  
  <p>store.sync()</p>
  
  <p>generates the warning...</p>
  
  <p>"[WARN][Ext.data.Batch#runOperation] Your identifier generation strategy for the model does not ensure unique id's. Please use the UUID strategy, or implement your own identifier strategy with the flag isUnique."</p>
  
  <p>When i hunt for the solution i found it is the problem with the id of model..in my case i am directly giving the fields in the store.there is no model file for me.I tried with some of the solution.nothing worked for me .Hope you can understand.Pls help me </p>
  
  <p>This is my code</p>
  
  <pre><code>Ext.define('MyAppp.store.MyStore', {
          extend:'Ext.data.Store',
          requires:['Ext.data.proxy.LocalStorage'],
          config: {
              remoteSort : true,
              identifier: {
                  type: 'uuid'
              },
              fields:[
                  {name:'firstname',type:'string'},    
                  {name:'lastname',type:'string'},
                  {name:'userID',type:'number'}
              ],
              proxy: {
                   type :'localstorage',
                   id:'LogInStore'
              }
          }
  });
  </code></pre>
  
  <p>Thanks in advance</p>