.withHeader("ONE", equalTo("abcd1234"))
.withHeader("two", matching("[a-z]{5}"))
.withHeader("Three", notMatching("[A-Z]+"))
.willReturn(aResponse().withStatus(204)));
WireMockResponse response = testClient.put("/case/insensitive",
withHeader("one", "abcd1234"),
withHeader("TWO", "thing"),
withHeader("tHrEe", "something"));
assertThat(response.statusCode(), is(204));
}