2.3.3 :004 > Post.new.attributes.keys - Post.protected_methods.to_a
=> ["id", "title", "body", "link", "post_creation_date", "created_at", "updated_at", "site_id", "user_link", "username", "why", "user_reputation", "score", "upvote_count", "downvote_count", "stack_exchange_user_id", "is_tp", "is_fp", "is_naa"]