private async Task <IActionResult> CheckUser()
        {
            var error = await userChecker.CheckUserExistence();

            if (error != null)
            {
                return(View("Error", error));
            }
            error = await userChecker.CheckUserBlockStatus();

            if (error != null)
            {
                return(View("Error", error));
            }
            return(null);
        }
        private async Task <IActionResult> CheckUser(string ownerUserName)
        {
            var error = await userChecker.CheckUserExistence();

            if (error != null)
            {
                return(View("Error", error));
            }
            error = await userChecker.CheckUserBlockStatus();

            if (error != null)
            {
                return(View("Error", error));
            }
            error = userChecker.CheckUserAccess(ownerUserName);
            if (error != null)
            {
                return(View("Error", error));
            }
            return(null);
        }