title: Sencha touch 2 error, identifier generation strategy for the model does not ensure unique id's, while working with a store
body: <p>In Sencha touch, I have defined a store:</p>
  
  <pre><code>Ext.define('TestApp.store.TokenStore', {
      extend: 'Ext.data.Store',    
      config: {
          model: 'TestApp.model.TokenModel',
          autoLoad: true,
          autoSync: true,
          proxy: {
              type: 'localstorage',
              // The store's ID enables us to eference the store by the following ID.
              // The unique ID of the Store will be the ID field of the Model.
              id: 'TokenStore'
          }
      }
  });
  </code></pre>
  
  <p>And a model for this store:</p>
  
  <pre><code>Ext.define('TestApp.model.TokenModel', {
      extend: 'Ext.data.Model',
      config:{
          fields: [ 
              {name: 'id', type: 'int' },
              {name:'token',type:'string'}
          ]
      }
  });
  </code></pre>
  
  <p>Now, inside the launch function of my App, I do the following:</p>
  
  <pre><code>// Get the store
  var tokenStore = Ext.getStore('TokenStore');
  
  // Add a token to the store
  tokenStore.add({'token': 1234});
  
  // Retrieve that token back:
  var token =  tokenStore.getAt(0).get('token');
  </code></pre>
  
  <p>Everything works, I see the token's value in the console, but I get the following warning:</p>
  
  <pre><code>[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.
  </code></pre>
  
  <p>What am I doing wrong?</p>