public void testMethodInvokation() throws Exception {
Calculator c = new Calculator();
Method method = c.getClass().getMethod("sum", new Class[]{double.class, double.class});
Object result = method.invoke(c, new Object[]{new Double(1.0), new Double(2.0)});
assertEquals("<double>3.0</double>", marshal(new DoubleConverter(),result));
Method method1 = c.getClass().getMethod("test", new Class[]{});
Object result1 = method1.invoke(c, new Object[]{});
assertTrue(result1.getClass().isArray());