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: 20230614180651_add_organization_id_to_namespaces.rb
    path of file: ./repos/gitlabhq/db/migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class AddOrganizationIdToNamespaces < Gitlab::Databa
    
  def up
    # This column already exists on some environments and it was reverted
    # in MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/122809
    return if column_exists?(:namespaces, :organization_id)

    add_column :namespaces, :organization_id, :bigint, default: DEFAULT_ORGANIZATION_ID, null: true # rubocop:disable Migration/AddColumnsToWideTables
  end