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: 20220316162257_remove_dead_tables_and_columns.rb
    path of file: ./repos/e621ng/db/migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class RemoveDeadTablesAndColumns < ActiveRecord::Migration[6.1]
  def u
    
  def up
    User.without_timeout do
      drop_table :post_appeals
      drop_table :favorite_groups
      drop_table :post_image_hashes
      drop_table :post_replacements
      drop_table :saved_searches
      drop_table :user_blacklisted_tags
      drop_table :post_updates
      drop_table :pixiv_ugoira_frame_data
      remove_column :artists, :is_banned
      remove_column :artist_versions, :is_banned
      remove_column :forum_topics, :min_level
      remove_column :dmails, :is_spam
      remove_column :posts, :pixiv_id
      remove_column :uploads, :referer_url
      remove_column :uploads, :context
      remove_column :uploads, :content_type
      remove_column :uploads, :file_path
      remove_column :uploads, :server
      change_column_null :users, :profile_about, false
      change_column_null :users, :profile_artinfo, false
    end
  end