@Override
 public ResponseMatcher doesNotExist() {
   return new WebServiceMessageMatcherAdapter(helper.doesNotExist());
 }
 @Override
 public ResponseMatcher evaluatesTo(String expectedValue) {
   return new WebServiceMessageMatcherAdapter(helper.evaluatesTo(expectedValue));
 }
 @Override
 public ResponseMatcher exists() {
   return new WebServiceMessageMatcherAdapter(helper.exists());
 }