code: public CloudFileDirectory getDirectoryReference(final String itemName) throws URISyntaxException,
              StorageException {
          Utility.assertNotNullOrEmpty("itemName", itemName);
  
          StorageUri subdirectoryUri = PathUtility.appendPathToUri(this.storageUri, itemName);
          return new CloudFileDirectory(subdirectoryUri, itemName, this.getShare());
      }
docs: Returns a reference to a {@link CloudFileDirectory} object that represents a directory in this directory.
  
  @param itemName
  A <code>String</code> that represents the name of the directory.
  
  @return A {@link CloudFileDirectory} object that represents a reference to the specified directory.
  
  @throws URISyntaxException
  If the resource URI is invalid.
  @throws StorageException