public void expectHeader(String headerName, Matcher<String> matcher) {
            Header firstHeader = response.getFirstHeader(headerName);
            String headerValue = firstHeader != null ? firstHeader.getValue() : null;
            assertThat(headerValue, matcher);
            assertNotNull(firstHeader);
        }
A simple http client for testing

@author Simon Thoresen Hult
@author bjorncs
container-core/src/test/java/com/yahoo/jdisc/http/server/jetty/SimpleHttpClient.java