public IActionResult AddOwner(int projectId, Guid userId)
        {
            var currentUser   = (User)HttpContext.Items["User"];
            var currentUserId = currentUser.UserId;
            var project       = _projectService.GetProject(projectId);

            if (project.ProjectCreatorId != currentUserId)
            {
                return(Unauthorized());
            }

            _projectService.AddOwner(userId, projectId);
            return(Ok());
        }