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: first_repeat_purchase_since.rb
    path of file: ./repos/solidus/core/app/models/spree/promotion/rules
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Spree
  class Promotion < Spree::Base
    modul
    
        def eligible?(order, _options = {})
          return false unless order.user

          last_order = last_completed_order(order.user)
          return false unless last_order

          last_order.completed_at < preferred_days_ago.days.ago
        end