# File lib/http_accept_language/parser.rb, line 61
    def compatible_language_from(available_languages)
      user_preferred_languages.map do |preferred| #en-US
        preferred = preferred.downcase
        preferred_language = preferred.split('-', 2).first

        available_languages.find do |available| # en
          available = available.to_s.downcase
          preferred == available || preferred_language == available.split('-', 2).first
        end
      end.compact.first
    end