public async void LeaseBlobChangeAsync_LeasedBlobToNewLeaseId_ChangesToMatchNewLeaseId()
        {
            IBlobServiceClient client = new BlobServiceClient(AccountSettings);
            var containerName = _util.GenerateSampleContainerName(_runId);
            var blobName = _util.GenerateSampleBlobName(_runId);
            _util.CreateContainer(containerName);
            _util.CreateBlockBlob(containerName, blobName);
            var leaseId = _util.LeaseBlob(containerName, blobName);
            var expectedLeaseId = Guid.NewGuid().ToString();

            var response = await client.LeaseBlobChangeAsync(containerName, blobName, leaseId, expectedLeaseId);

            Assert.AreEqual(expectedLeaseId, response.LeaseId);
            _util.AssertBlobIsLeased(containerName, blobName, expectedLeaseId);
        }
        public async void LeaseBlobChangeAsync_NonexistentBlob_ThrowsBlobNotFoundException()
        {
            IBlobServiceClient client = new BlobServiceClient(AccountSettings);
            var containerName = _util.GenerateSampleContainerName(_runId);
            var blobName = _util.GenerateSampleBlobName(_runId);
            _util.CreateContainer(containerName);
            var expectedLeaseId = Guid.NewGuid().ToString();

            await client.LeaseBlobChangeAsync(containerName, blobName, FakeLeaseId, expectedLeaseId);

            // expects exception
        }
        public async void LeaseBlobChangeAsync_NonLeasedBlob_ThrowsLeaseNotPresentException()
        {
            IBlobServiceClient client = new BlobServiceClient(AccountSettings);
            var containerName = GenerateSampleContainerName();
            var blobName = GenerateSampleBlobName();
            CreateContainer(containerName);
            CreateBlockBlob(containerName, blobName);
            var expectedLeaseId = Guid.NewGuid().ToString();

            await client.LeaseBlobChangeAsync(containerName, blobName, FakeLeaseId, expectedLeaseId);

            // expects exception
        }