Post["/serializer"] = _ =>
{
    var model = new FakeSerializerModel {CreatedOn = new DateTime(2014, 01, 30)};
    this.BindTo(model);
    return model;
};

[Fact]
public void Should_BindTo_Existing_Instance_Using_Body_Serializer()
{
    //Given
    var model = new FakeSerializerModel { Name = "Marsellus Wallace" };

    //When
    var result = browser.Post("/serializer", with =>
    {
        with.JsonBody(model);
        with.Accept("application/json");
    });

    var resultModel = result.Body.DeserializeJson<FakeSerializerModel>();

    //Then
    Assert.Equal("Marsellus Wallace", resultModel.Name);
    Assert.Equal(new DateTime(2014, 01, 30), resultModel.CreatedOn);
}