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: add_adm.rb
    path of file: ./repos/rpush/lib/generators/templates
    
    the code of the file until where you have to start completion: class AddAdm < ActiveRecord::Migration[5.0]
  module Rapns
    class Notification < ActiveRecord::Ba
    
  def self.down
    AddAdm::Rapns::Notification.where(type: 'Rapns::Adm::Notification').delete_all

    remove_column :rapns_apps, :client_id
    remove_column :rapns_apps, :client_secret
    remove_column :rapns_apps, :access_token
    remove_column :rapns_apps, :access_token_expiration
  end