Sync attributes for a single post from WP API data.

        :param existing_post: Post object that needs to be sync'd
        :param api_post: the API data for the Post
        :param author: the Author object of the post (should already exist in the db)
        :param post_categories: the Categories to attach to the post (should already exist in the db)
        :param post_tags: the Tags to attach to the post (should already exist in the db)
        :param post_media_attachments: the Medias to attach to the post (should already exist in the db)
        :return: None

def process_existing_post(existing_post, api_post, author, post_categories, post_tags, post_media_attachments):
        """
        Sync attributes for a single post from WP API data.

        :param existing_post: Post object that needs to be sync'd
        :param api_post: the API data for the Post
        :param author: the Author object of the post (should already exist in the db)
        :param post_categories: the Categories to attach to the post (should already exist in the db)
        :param post_tags: the Tags to attach to the post (should already exist in the db)
        :param post_media_attachments: the Medias to attach to the post (should already exist in the db)
        :return: None
        """
        # don't bother checking what's different, just update all fields
        existing_post.author = author
        existing_post.post_date = api_post["date"]
        existing_post.modified = api_post["modified"]
        existing_post.title = api_post["title"]
        existing_post.url = api_post["URL"]
        existing_post.short_url = api_post["short_URL"]
        existing_post.content = api_post["content"]
        existing_post.excerpt = api_post["excerpt"]
        existing_post.slug = api_post["slug"]
        existing_post.guid = api_post["guid"]
        existing_post.status = api_post["status"]
        existing_post.sticky = api_post["sticky"]
        existing_post.password = api_post["password"]
        existing_post.parent = api_post["parent"]
        existing_post.post_type = api_post["type"]
        existing_post.likes_enabled = api_post["likes_enabled"]
        existing_post.sharing_enabled = api_post["sharing_enabled"]
        existing_post.like_count = api_post["like_count"]
        existing_post.global_ID = api_post["global_ID"]
        existing_post.featured_image = api_post["featured_image"]
        existing_post.format = api_post["format"]
        existing_post.menu_order = api_post["menu_order"]
        existing_post.metadata = api_post["metadata"]
        existing_post.post_thumbnail = api_post["post_thumbnail"]

        WPAPILoader.process_post_many_to_many_field(existing_post, "categories", post_categories)
        WPAPILoader.process_post_many_to_many_field(existing_post, "tags", post_tags)
        WPAPILoader.process_post_many_to_many_field(existing_post, "attachments", post_media_attachments)

        existing_post.save()