text: Ext.define('Tutorial.model.Product', {
      extend: 'Ext.data.Model',
      requires:[
          'Tutorial.model.Price',
          'Tutorial.model.Inventory',
          'Tutorial.model.Category',
          'Tutorial.model.Tax',
      ],
      fields: [
          { name: 'id', type: 'int' },
          { name: 'name', type: 'string' },
          { name: 'description', type: 'string' },
          { name: 'reference', type: 'string'},
          { name: 'status', type: 'string' },
          { name: 'productKey', type: 'string' }
      ],
      hasMany: [
          {
              model: 'Tutorial.model.Tax',                                                  
              name: 'tax',
              associationKey: 'tax' 
          }, {                                                              
              model: 'Tutorial.model.Price',                                                  
              name: 'price',
              associationKey: 'price'                                
          }, {                                                              
              model: 'Tutorial.model.Inventory',                                                  
              name: 'inventory',
              associationKey: 'inventory'                                              
          }, {
              model: 'Tutorial.model.Category',                                                  
              name: 'category',
              associationKey: 'category'
          }
      ],
      proxy: {
          type: 'rest',
          url: '/api/product',
          reader: {
              type: 'json',
              rootProperty: 'data'
          },
          writer: {
              type: 'json',
              writeRecordId: false,
              writeAllFields: false
          }
      },
  });