mustella/tests/DownloadProgressBar/SWFs/assets/MainSpark.mxml

<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark"
    	width="300" height="250" preloader="SparkDelayedProgressBar">
    	<s:layout>
    	    <s:HorizontalLayout />
    	</s:layout>
    <s:Button label="Test"/>
    <s:Button label="Test"/>
    <s:Button label="Test"/>

</s:Application>