@Test
 public void testTransformModifiesOutboundValue() throws Exception {
   HttpAction<HttpGet> action = get("/constraint/ONE/TWO");
   Assert.assertEquals(
       action.getContextPath() + "/outbound/three",
       action.getResponseHeaderValues("three").get(0));
 }
 @Test
 public void testTransformModifiesIncomingValue() throws Exception {
   HttpAction<HttpGet> action = get("/constraint/ONE/TWO");
   Assert.assertEquals("ONE", action.getResponseHeaderValues("one").get(0));
   Assert.assertEquals("two", action.getResponseHeaderValues("two").get(0));
 }