private static void ValidateRequest(RetrieveBetsQuery request)
 {
     if (request is null)
     {
         throw new ArgumentNullException(nameof(request), $"request cannot be null");
     }
 }
        public async Task <IReadOnlyCollection <BetDto> > Handle(RetrieveBetsQuery request, CancellationToken cancellationToken)
        {
            ValidateRequest(request);

            return(await _betRepository.GetBetsForMemberAsync());
        }