function sasSample () {
  console.log('Starting sasSample.');

  // Create the container.
  createContainer(function () {

    // Create a blob.
    createBlob( function () {

      // Create a shared access signature and use it to download the blob just created.
      downloadBlobUsingSharedAccessSignature(function () {

        // Add Shared Access policies to the container
        createPolicies(function () {

          // Use the read policy just created
          usePermissions(function () {

            // Delete the container
            deleteContainer(function () {
              console.log('Ending sasSample.');
            });
          });
        });
      });
    });
  });
}
In this sample, we demonstrate how to generate and use the blob level shared access signature and the container level
shared access signature.

In the blob level shared access signature sample, there are the following steps: 

1. Create a container and a blob.

2. Generate a shared access signature for the blob and download the blob using it.

3. Upload a "ReadWrite" policy and a "Read" permission to the container.

4. Generate a shared access signature for the blob using the policy id and download the blob using it.