private function appendChartCdnCall()
{
$txt = $this->getContentFromTemplate('ChartCdn', $this->tokens);
$contents = file_get_contents($this->files['Index']);
$classParts = explode("<!-- End Grid Requirement -->", $contents, 2);
$txt = $classParts[0] . "<!-- End Grid Requirement -->" . "\n\n" . $txt . $classParts[1];
$handle = fopen($this->files['Index'], "w");
fwrite($handle, $txt);
fclose($handle);
return $this;
}