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: product_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 ProductBased
      def initialize(product)
        @product = product
        @settings = Settings.find_or_initialize_by
    
      def results
        @results ||=
          begin
            results = []

            @settings.sources.each do |source|
              results.push(*send(source))
              results.uniq!

              break if results.length >= max_results
            end

            results.take(max_results)
          end