public async Task <IActionResult> Register(ClientCredentialDto clientCredentials)//string userName, string password)[FromBody]
        {
            if (clientCredentials == null)
            {
                return(BadRequest("Client request not sent"));
            }

            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }

            if (await _repo.ClientIdExists(clientCredentials.ClientID))
            {
                return(BadRequest("Client Id already exists"));
            }
            var createdCredential = await _repo.Register(clientCredentials);//http://example.org/myitem

            if (createdCredential == null)
            {
                return(Ok(clientCredentials.ClientID + " has not been created"));
            }
            else
            {
                return(Created("http://FOSObjects.org/myitem", new { message = clientCredentials.Id + " has been created" }));
            }
        }