title: google.visualization.PieChart is not a constructor
body: <p>I am using pie chart to show the data here is my code  I have added the following script</p>
  
  <pre><code>&lt;script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"&gt;&lt;/script&gt;
  
      &lt;script type="text/javascript"&gt;
          google.charts.load('current', { 'packages': ['corechart', 'gauge'] });
  </code></pre>
  
  <p>and my function which is used to display chat:-</p>
  
  <pre><code>self.DrawServiceGraph = function (obj) {
                  var dataArray = new Array();
                  dataArray.push(['Services', 'Total']);
                  var subCat = ko.utils.arrayFirst(self.SelectedServiceSubCategoryList(), function (o) { return o.Id === obj.Id; });
                  if (subCat !== undefined) {
                      $.each(subCat.SSC_List(), function (index, item) {
                          var value = parseInt(item.Value());
                          dataArray.push([item.SSC_Name, value]);
                      });
  
                      var data = google.visualization.arrayToDataTable(dataArray);
  
                      var options = {
                          title: '', height: 230, width: 330,
                          chartArea: { left: 0, width: '100%' },
                          legend: { position: 'right', alignment: 'start', maxLines: 5, textStyle: { fontSize: 10 } }
                      };
  
                      var chart = new google.visualization.PieChart(document.getElementById('Services-chart' + obj.Id));
                      chart.draw(data, options);
                  }
              }
  </code></pre>
  
  <p>Then i got the error from line:</p>
  
  <p><strong>google.visualization.Pie Chart is not a constructor</strong> and 
  <strong>google.visualization.arrayToDataTable is not a constructor</strong></p>
  
  <p>What should be the possible solutions to avoid this errors?</p>