def _task_callback(task):
    """Print task status.

    :param task: XML representation of a task resource
    :type task: lxml.objectify.ObjectifiedElement
    """
    message = '{0}: {1}, status: {2}'.format(task.get('operationName'),
        task.get('operation'), task.get('status'))
    if hasattr(task, 'Progress'):
        message += ', progress: %s%%' % task.Progress
    print(message)
