public function testNoTargetPath() {
$content = 'body { background: url(foo.gif); }';
$asset = new StringAsset($content);
$asset
->load();
$filter = new CssRewriteFilter();
$filter
->filterDump($asset);
$this
->assertEquals($content, $asset
->getContent(), '->filterDump() urls are not changed without urls');
}