@Test
public void testPlainFilter() {

    Filter f = ff.greater(ff.property("attribute"), ff.literal(10));
    Rule r = sb.createRule(sb.createPointSymbolizer());
    r.setFilter(f);
    
    StyleAttributeExtractor extractor = new StyleAttributeExtractor();
    r.accept(extractor);
    
    Set<String> atts = extractor.getAttributeNameSet();
    assertTrue(atts.contains("attribute"));
    assertEquals(1, atts.size());
    assertTrue(extractor.getDefaultGeometryUsed());
}