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: order_based.rb
    path of file: ./repos/workarea/core/app/queries/workarea/recommendation
    
    the code of the file until where you have to start completion: module Workarea
  module Recommendation
    class OrderBased
      def initialize(order)
        @order = order
      end

    
    
      def related_product_ids
        query = Workarea::Search::RelatedProducts.new(
          product_ids: order_product_ids,
          category_ids: order_category_ids,
          exclude_product_ids: order_product_ids
        )

        query.results.map { |r| r[:catalog_id] }.first(max_results)
      end