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: 20170209191230_rename_straw_to_litter_in_animal_housing_mulching_procedure.rb
    path of file: ./repos/ekylibre/db/migrate
    
    the code of the file until where you have to start completion: class RenameStrawToLitterInAnimalHousingMulchingProcedure < ActiveRecord::Migration[4.2]
  def change
    reversible do |dir|
      dir.up do
        execute <<-SQL
        UPDATE
          intervention_parameters AS iparam
          SET reference_name = 'litter'
          FROM interventions
          WHERE (iparam.reference_name = 'straw'
            AND interventions.procedure_name = 'animal_housing_mulching'
            AND iparam.intervention_id = interventions.id)
        SQL
      end
      dir.d
    
  def change
    reversible do |dir|
      dir.up do
        execute <<-SQL
        UPDATE
          intervention_parameters AS iparam
          SET reference_name = 'litter'
          FROM interventions
          WHERE (iparam.reference_name = 'straw'
            AND interventions.procedure_name = 'animal_housing_mulching'
            AND iparam.intervention_id = interventions.id)
        SQL
      end
      dir.down do
        execute <<-SQL
        UPDATE
          intervention_parameters AS iparam
          SET reference_name = 'straw'
          FROM interventions
          WHERE (iparam.reference_name = 'litter'
            AND interventions.procedure_name = 'animal_housing_mulching'
            AND iparam.intervention_id = interventions.id)
        SQL
      end
    end
  end