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: 20180706150714_convert_to_markdown.rb
    path of file: ./repos/openproject/db/migrate
    
    the code of the file until where you have to start completion: #-- copyright
# OpenProject is an open source project management software.
# Copyright (C) 2012-2024 the OpenProject GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the 
    
  def up
    setting = Setting.where(name: 'text_formatting').pluck(:value)
    return unless setting && setting[0] == 'textile'

    if ENV['OPENPROJECT_SKIP_TEXTILE_MIGRATION'].present?
      warn <<~WARNING
        Your instance is configured with Textile text formatting, this means you have likely been running OpenProject before 8.0.0

        Since you have requested skip the textile migration, your data will NOT be converted. You can do this in a subsequent step:

        $> bundle exec rails runner "OpenProject::TextFormatting::Formats::Markdown::TextileConverter.new.run!"

        or in a packaged installation:

        $> openproject run bundle exec rails runner "OpenProject::TextFormatting::Formats::Markdown::TextileConverter.new.run!"

        For more information, please visit this page: https://www.openproject.org/textile-to-markdown-migration

      WARNING
      return
    end

    if setting && setting[0] == 'textile'
      raise <<~ERROR
        You appear to be upgrading from an old version of OpenProject using textile text formatters.

        OpenProject version 13.0 no longer provides the migration from Textile to Markdown.
        First upgrade to any 12.x version, before performing the upgrade to 13.0
      ERROR
    end