public void WhenCalling_GetImageAsync_WithNullParameter_Should_ThrowArgumentNullException()
        {
            var sut = new ImagesCache(A.Dummy <IDistributedCache>());

            sut.Awaiting(ic => ic.GetImageAsync(null))
            .Should().ThrowExactly <ArgumentNullException>();
        }
        public void WhenCalling_CacheImageAsync_WithNullImageParameter_Should_ThrowArgumentNullException()
        {
            var distributedCache = A.Dummy <IDistributedCache>();
            var sut = new ImagesCache(distributedCache);

            sut.Awaiting(ic => ic.CacheImageAsync(new ImageCacheKey("01_04_2019_001103"), null))
            .Should().ThrowExactly <ArgumentNullException>();
        }
        public void WhenCalling_CacheImageAsync_WithNullKeyParameter_Should_ThrowArgumentNullException()
        {
            var distributedCache = A.Dummy <IDistributedCache>();
            var sut = new ImagesCache(distributedCache);

            sut.Awaiting(ic => ic.CacheImageAsync(null, new Image()))
            .Should().ThrowExactly <ArgumentNullException>();
        }