<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>MyTestBedPurecode</title>
<link rel="stylesheet" type="text/css" href="ext/resources/css/ext-all.css"/>
<script type="text/javascript" src="ext/ext-debug.js"></script>
<script type="text/javascript" src="app.js"></script>
<script type="text/javascript" src="app/overrides/CustomXmlReader.js"></script>
</head>
<body></body>
</html>
use ext-debug.js( instead of ext-all-dev.js) will ensure we only load class when needed.
and the file size is small so the app can be easy debug.