gistfile1.cs

foreach (var model in models)
                {
                    if (model.first_name == null)
                    {

                        return Request.CreateResponse(HttpStatusCode.BadRequest,
                                                      new ErrorResponse[]
                                                          {new ErrorResponse(ErrorCodes.FirstNameRequired)});

                        //OR record this element in the array and then create an array without these elements and fail silently
                    }
                }