title: Trying to acquire a lease on a new blockblob gets me a 404
body: <p>When I try to acquire a lease on a CloudBlockBlob that I want to create I get a 404. </p>
  
  <pre><code>lease = blockBlob.AcquireLease(_leaseTimeOut, null);
  blockBlob.UploadFromByteArrayAsync(contentBytes, 0, contentBytes.Length).Wait();
  </code></pre>
  
  <p>I can imagine that it is because it doesn't exist yet, however how do I use leases on a blob that I want to create. I don't want concurrency errors here.</p>