public Activation GetById(Guid id)
        {
            ActivationIdSpecification specification = new ActivationIdSpecification(id);

            return(_dbSet
                   .AsNoTracking()
                   .FirstOrDefault(specification.ToExpression()));
        }
        public Activation GetById(Guid id)
        {
            ActivationIdSpecification spec = new ActivationIdSpecification(id);

            return(_activations.AsQueryable().FirstOrDefault(spec.ToExpression()));
        }