You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: flickr_onebox.rb
    path of file: ./repos/discourse/lib/onebox/engine
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require_relative "./opengraph_image"

module Onebox
  module Engine
    class FlickrOnebox
      include Engine
      include StandardEmbed

      matches_regexp(%r{^https?://www\.flickr\.com/photos/})
      always_https

      def to_html
        og = get_opengraph
        return album_html(og) if og.url =~ %r{/sets/}
        return image_html(og) if !og.image.nil?
        nil
      end

      private

      def album_html(og)
        escaped_url = ::Onebox::Helpers.normalize_url_for_output(url)
        album_title = "[Album] #{og.title}"

        <<-HTML
          <div class='one
    
      def album_html(og)
        escaped_url = ::Onebox::Helpers.normalize_url_for_output(url)
        album_title = "[Album] #{og.title}"

        <<-HTML
          <div class='onebox flickr-album'>
            <a href='#{escaped_url}' target='_blank' rel='noopener'>
              <span class='outer-box' style='max-width:#{og.image_width}px'>
                <span class='inner-box'>
                  <span class='album-title'>#{album_title}</span>
                </span>
              </span>
              <img src='#{og.secure_image_url}' #{og.title_attr} height='#{og.image_height}' width='#{og.image_width}'>
            </a>
          </div>
        HTML
      end