title: ExtJS gauge chart series - setValue() is not a function
body: <p>I have a piece of code looking like this:</p>
  
  <pre><code>var myChart = this.items[i].items[j].down().down();
  myChart.series.items[0].setValue(30);
  </code></pre>
  
  <p>myChart is well defined. When I spy it in firebug, it contains the chart.</p>
  
  <p>I understood that gauge is not a type of chart but a type of series, so I really don't understand why I get the error "setValue is not a function" !</p>
  
  <p>If someone could help, it would be really cool cause I'm very annoyed with that.</p>
  
  <p>Here's my view definition:</p>
  
  <pre><code>Ext.define('MyApp.view.portlet.GaugePortlet', {
      extend: 'Ext.panel.Panel',
      alias: 'widget.gaugeportlet',
      height: 300,
      requires: [
          'Ext.data.JsonStore',
          'Ext.chart.theme.Base',
          'Ext.chart.series.Series',
          'Ext.chart.series.Line',
          'Ext.chart.axis.Numeric',
          'Ext.chart.*',
          'Ext.chart.axis.Gauge',
          'Ext.chart.series.*'],
  
      initComponent: function () {
  
          Ext.apply(this, {
              layout: 'fit',
              items: {
                  xtype: 'chart',
                  animate: {
                      easing: 'elasticIn',
                      duration: 1000
                  },
                  legend: {
                      position: 'bottom'
                  },
                  axes: [{
                      type: 'gauge',
                      position: 'gauge',
                      minimum: 0,
                      maximum: 2,
                      steps: 10
                  }],
                  series: [{
                      type: 'gauge',
                      donut: false,
                      colorSet: ['#F49D10', '#ddd']
                  }]
              }
          });
  
          this.callParent(arguments);
      }
  });
  </code></pre>
  
  <p>I don't want to work with dynamic stores for now, I just want to test with setting an hardcoded value.</p>
  
  <p>Thanks</p>