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: 20220922014326_fix_string_types_on_multiple_tables.rb
    path of file: ./repos/danbooru/db/migrate
    
    the code of the file until where you have to start completion: class FixStringTypesOnMultipleTables < ActiveRecord::Migration[7.0]
  def up
    change_column :artist_urls, :url, :string
    change_column :saved_searches, :query, :string
    change_column :tag_aliases, :status, :string
    change_column :tag_implications, :status, :string
    change_column :uploads, :source, :string
    change_colu
    
  def down
    change_column :artist_urls, :url, :text
    change_column :saved_searches, :query, :text
    change_column :tag_aliases, :status, :text
    change_column :tag_implications, :status, :text
    change_column :uploads, :source, :text
    change_column :uploads, :status, :text
    change_column :uploads, :referer_url, :text
    change_column :post_replacements, :original_url, :text
    change_column :post_replacements, :replacement_url, :text

    change_column :forum_topics, :title, :string
    change_column :pools, :name, :string
  end