public Map<String, String> getHeaders()
  {
    return _headers;
  }
@Test
  public void testHeadersCaseInsensitiveSet()
  {
    final long id = 42l;
    GetRequestBuilder<Long, TestRecord> builder = generateDummyRequestBuilder();
    Request<TestRecord> request = builder
        .id(id)
        .setHeader("header", "value1")
        .setHeader("HEADER", "value2")
        .build();
    Assert.assertEquals(request.getHeaders().get("header"), "value2");
  }