public async Task AddNew(AddAuthorRequest addAuthorRequest) { if (addAuthorRequest.Name == null) { throw new BadRequestException("Imie jest puste"); } if (addAuthorRequest.Age < 0) { throw new BadRequestException("Chłop się jeszcze nie urodził"); } Author author = new Author() { Id = Guid.NewGuid(), Name = addAuthorRequest.Name, Age = addAuthorRequest.Age }; await _authorRepository.AddNew(author); }