@Test
 public void testMultipleNoCacheFields() {
   CacheControl cc = new CacheControl();
   cc.setNoCache(true);
   cc.getNoCacheFields().add("c");
   cc.getNoCacheFields().add("d");
   assertTrue(cc.toString().contains("no-cache=\"c,d\""));
 }
 @Test
 public void testMultiplePrivateFields() {
   CacheControl cc = new CacheControl();
   cc.setPrivate(true);
   cc.getPrivateFields().add("a");
   cc.getPrivateFields().add("b");
   assertTrue(cc.toString().contains("private=\"a,b\""));
 }
 @Test
 public void testCacheExtensionToString() {
   CacheControl cc = new CacheControl();
   cc.getCacheExtension().put("ext1", null);
   cc.getCacheExtension().put("ext2", "value2");
   cc.getCacheExtension().put("ext3", "value 3");
   String value = cc.toString();
   assertTrue(value.indexOf("ext1") != -1 && value.indexOf("ext1=") == -1);
   assertTrue(value.indexOf("ext2=value2") != -1);
   assertTrue(value.indexOf("ext3=\"value 3\"") != -1);
 }
 @Test
 public void testNoCacheDisabled() {
   CacheControl cc = new CacheControl();
   cc.setNoCache(false);
   assertEquals("no-transform", cc.toString());
 }
 @Override
 public Builder cacheControl(CacheControl control) {
   webClient.header(HttpHeaders.CACHE_CONTROL, control.toString());
   return this;
 }