public void Can_check_used_disk_per_store()
        {
            CloudInfrastructure cloud = new CloudInfrastructure();

            cloud.CreateStore("myImages");
            cloud.UploadDocument("myImages", "picture.jpeg");

            // we suppose all documents have the same size which is 0.1gb
            Assert.AreEqual(0.100, cloud.UsedDiskStore("myImages"), 0.00001);

            cloud.UploadDocument("myImages", "profile.png");
            // a second document was inserted, used disk in "muImages" = 200mb
            Assert.AreEqual(0.200, cloud.UsedDiskStore("myImages"), 0.00001);
        }