@Test
public void parseCSS() throws IOException {

    retriever.processFromStream(CSSFileProcessorTest.class.getResourceAsStream("/css/test.css"), proc);
    CssFile file = proc.getCss();
    List<CssRule> rules = file.get(new Tag("body"));
    Assert.assertTrue(rules.size() == 1);
    Assert.assertTrue("margin not found.", rules.get(0).getNormalDeclarations().containsKey("margin"));
    Assert.assertEquals("Value for margin not correct.", "20px", rules.get(0).getNormalDeclarations().get("margin"));
}