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: 20190313140443_relax_fixed_asset_constraints_for_none_deprecation_method.rb
    path of file: ./repos/ekylibre/db/migrate
    
    the code of the file until where you have to start completion: class RelaxFixedAssetConstraintsForNoneDeprecationMethod < ActiveRecord::Migration[4.2]
  def change
    reversible d
    
  def change
    reversible do |r|
      r.up do
        change_column :fixed_assets, :stopped_on, :date, null: true
        change_column :fixed_assets, :allocation_account_id, :integer, null: true
      end

      r.down do
        change_column :fixed_assets, :stopped_on, :date, null: false
        change_column :fixed_assets, :allocation_account_id, :integer, null: false
      end
    end
  end