public void SetUp()
{
_response = new Response(HttpStatusCode.OK);
_response.Header("field1", "value1");
_response.Headers((IEnumerable<Header>)new[] { new Header("field2", "value2"), new Header("field3", "value3") });
_response.Headers(new Header("field4", "value4"), new Header("field5", "value5"));
}