@Test
public void testGeometryTransformation() {

    PointSymbolizer ps = sb.createPointSymbolizer();
    ps.setGeometry(ff.function("offset", ff.property("the_geom"), ff.property("offx"), ff.property("offy")));
    Rule r = sb.createRule(ps);
    
    StyleAttributeExtractor extractor = new StyleAttributeExtractor();
    r.accept(extractor);
    
    Set<String> atts = extractor.getAttributeNameSet();
    assertEquals(3, atts.size());
    assertTrue(atts.contains("the_geom"));
    assertTrue(atts.contains("offx"));
    assertTrue(atts.contains("offy"));
    assertFalse(extractor.getDefaultGeometryUsed());
}