@Test
    void requireThatEntryIsUnmodifiable() {
        Headers headers = new Headers();
        headers.put("foo", "bar");
        Map.Entry<String, String> entry = headers.entries().get(0);
        try {
            entry.setValue("baz");
            fail();
        } catch (UnsupportedOperationException e) {

        }
    }
@author Simon Thoresen Hult
@author Einar M R Rosenvinge
application/src/test/java/com/yahoo/application/container/handler/HeadersTestCase.java