Does this code make sense for creating and updating the Twitter field?
```
def set_avatar
    if missing_image?
      twitter_response = get_twitter_image_url if twitter
      self.image_url = twitter_response
    end
  end

  def missing_image?
    image_url.blank? || image_url == "missing_image.png" || HTTParty.get(self.image_url).code != 200
  end

  def get_twitter_image_url
    begin
      client = Twitter::REST::Client.new do |config|
        config.consumer_key = ENV['TWITTER_CONSUMER_KEY']
        config.consumer_secret = ENV['TWITTER_CONSUMER_SECRET']
        config.access_token = ENV['TWITTER_ACCESS_TOKEN']
        config.access_token_secret = ENV['TWITTER_ACCESS_TOKEN_SECRET']
      end
      return client.user(self.twitter).profile_image_uri_https(:bigger).to_s
    rescue Twitter::Error::NotFound
      return "missing_image.png"
    end
  end
```