public UnitOfWork(FootballTeamsContext context)
        {
            if (context == null)
            {
                throw new ArgumentNullException();
            }

            this.context = context;
        }
        public EfCoreRepository(FootballTeamsContext context)
        {
            if (context == null)
            {
                throw new ArgumentException("Context is null !");
            }

            this.context = context;
            this.set     = this.context.Set <T>();
        }