@Test
public void shouldSerializeResponse() {

    Headers headers = new Headers();
    headers.setHeader("Header", "Value");
    headers.setHeader("SomeOtherHeader", "123");
    assertThat(headersSerializer.serialize(headers), anyOf(
            is("SomeOtherHeader: 123\r\nHeader: Value\r\n\r\n"),
            is("Header: Value\r\nSomeOtherHeader: 123\r\n\r\n")
    ));
}