def process_actor(api_actor):
    """Parse an actor definition from an API result."""
    api_actor = api_actor or {}
    return {
        'id': api_actor.get('id'),
        'name': api_actor.get('displayName'),
        'url': api_actor.get('url'),
        'image_url': api_actor.get('image', {}).get('url'),
    }