public async Task CategoryExistsReturnsFalseIfCategoryDoesntExists()
        {
            var options = new DbContextOptionsBuilder <ApplicationDbContext>()
                          .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()).Options;
            var dbContext = new ApplicationDbContext(options);

            var repository = new EfDeletableEntityRepository <Category>(dbContext);

            var service  = new CategoriesService(repository);
            var category = new Category()
            {
                Id = 1,
            };

            dbContext.Add(category);
            await dbContext.SaveChangesAsync();

            var result = service.CategoryExists(2);

            Assert.False(result);
        }