def METHOD_NAME(self, entity, expired_days=3, topic=None):
    """
    Get posts related to entity, optionally filtered by days and topic
    """
    today = datetime.today()
    posts = self.data[entity]["posts"]
    filtered = list()
    for post in posts:
        post_day = datetime.fromtimestamp(int(post["created_utc"]))  # filter news by timedate and topic:
        if topic is not None and post["topic"] != topic:  # topic
            continue
        if (today - post_day).days > expired_days and post["content_category"] == "news":  # date
            continue
        filtered.append(post)
    return filtered