public async Task TestCheckId_IsNotInList()
        {
            var guid   = Guid.NewGuid();
            var result = await _exchangeService.CheckId(guid);

            Assert.IsTrue(result.IsFree);
        }
        public async Task <IActionResult> CheckId([FromRoute] Guid guid)
        {
            if (!ModelState.IsValid)
            {
                throw new ClientSideException(ExceptionType.WrongParams, JsonConvert.SerializeObject(ModelState.Errors()));
            }

            var result = await _exchangeContractService.CheckId(guid);

            return(Ok(new CheckIdResponse
            {
                IsOk = result.IsFree,
                ProposedId = result.ProposedId,
            }));
        }