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: 20231120070345_cleanup_ci_stages_pipeline_id_bigint.rb
    path of file: ./repos/gitlabhq/db/post_migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class CleanupCiStagesPipelineIdBigint < Gitlab::Database::Migration[2.2]
  include Gitlab::Database::MigrationHelpers::WraparoundAutovacuum

  disable_ddl_transaction!
  milestone "16.7"

  TABLE = :ci_stages
  REFERENCING_TABLE 
    
  def down
    return unless can_execute_on?(:ci_pipelines, :ci_stages)

    restore_conversion_of_integer_to_bigint(TABLE, [COLUMN])

    INDEXES.each do |index_name, (columns, options)|
      add_concurrent_index(TABLE, columns, name: index_name, **options)
    end

    add_concurrent_foreign_key(
      TABLE, REFERENCING_TABLE,
      column: OLD_COLUMN, name: OLD_FK_NAME,
      on_delete: :cascade, validate: true, reverse_lock_order: true
    )
  end