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: tags_controller.rb
    path of file: ./repos/mastodon/app/controllers
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class TagsController < ApplicationController
  include SignatureVerification
  include WebAppControllerConcern

  PAGE_SIZE     = 20
  PAGE_SIZE_MAX = 200

  vary_by 
    
  def show
    respond_to do |format|
      format.html do
        expires_in(15.seconds, public: true, stale_while_revalidate: 30.seconds, stale_if_error: 1.hour) unless user_signed_in?
      end

      format.rss do
        expires_in 0, public: true
      end

      format.json do
        expires_in 3.minutes, public: public_fetch_mode?
        render json: collection_presenter, serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, content_type: 'application/activity+json'
      end
    end
  end