code: @DoesServiceRequest
      public Iterable<ListFileItem> listFilesAndDirectories(FileRequestOptions options, OperationContext opContext) {
          return listFilesAndDirectories(null /* prefix */, options, opContext);
      }
docs: Returns an enumerable collection of file and directory items for the directory.
  
  @param options
  A {@link FileRequestOptions} object that specifies any additional options for the request. Specifying
  <code>null</code> will use the default request options from the associated service client (
  {@link CloudFileClient}).
  @param opContext
  An {@link OperationContext} object that represents the context for the current operation. This object
  is used to track requests to the storage service, and to provide additional runtime information about
  the operation.
  
  @return An enumerable collection of {@link ListFileItem} objects that represent the file and directory items in
  this directory.
  
  @throws StorageException
  If a storage service error occurred.
  @throws URISyntaxException
  If the resource URI is invalid.