/**
     * @dataProvider provideUrls
     */
    public function testUrls($format, $sourceUrl, $targetUrl, $inputUrl, $expectedUrl)
    {
        $asset = new StringAsset(sprintf($format, $inputUrl), array(), $sourceUrl);
        $asset->setTargetUrl($targetUrl);
        $asset->load();

        $filter = new CssRewriteFilter();
        $filter->filterLoad($asset);
        $filter->filterDump($asset);

        $this->assertEquals(sprintf($format, $expectedUrl), $asset->getContent(), '->filterDump() rewrites relative urls');
    }