https://bugs.openjdk.org/browse/JDK-8276559 introduced a new default method HEAD() on the java.net.http.HttpRequest.Builder interface.

We currently have tests that verify the behaviour of this method when it's overridden by the implementing builder class. But we do not have any test which verifies the default HEAD() method's implementation, when that method isn't overridden. We should introduce a new test.