public void GetSendableStringDictionary_correct()
        {
            var findDebts = new FindDebts
            {
                Number     = "123",
                ToDate     = new DateTime(2010, 1, 1),
                FromDate   = null,
                Attributes = new Dictionary <string, string>()
                {
                    { "a", "b" },
                    { "1", "2" }
                }
            };


            var dictionary = findDebts.SendableStringDictionary;

            TestingUtils.AssertDictionaryContainsItems(dictionary,
                                                       ("number", "123"),
                                                       ("to_date", "2010-01-01"),
                                                       ("from_date", ""),
                                                       ("attributes[a]", "b"),
                                                       ("attributes[1]", "2")
                                                       );
        }