List<nsIDOMNode> buttons = crawler.selector().add(Filters.button()).list();
assertEquals(2, buttons.size());
assertEquals("I am a button", XPCOMConverter.getAttributeValue(buttons.get(0), "value"));
assertEquals("I am also a button", XPCOMConverter.asPlainText(buttons.get(1)));
List<nsIDOMNode> checkboxes = crawler.selector().add(Filters.checkbox()).list();
assertEquals(1, checkboxes.size());
assertEquals("I am a checkbox", XPCOMConverter.getAttributeValue(checkboxes.get(0), "value"));
List<nsIDOMNode> files = crawler.selector().add(Filters.file()).list();
assertEquals(1, files.size());