protected function createAppXmlFile()
{
$appName = self::APP_NAME;
$appXmlFileContents = <<<EOD
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Properties xmlns="http://schemas.openxmlformats.org/officeDocument/2006/extended-properties">
<Application>{$appName}</Application>
<TotalTime>0</TotalTime>
</Properties>
EOD;
$this->createFileWithContents($this->docPropsFolder, self::APP_XML_FILE_NAME, $appXmlFileContents);
return $this;
}