# File lib/faker/address.rb, line 26
      def zip_code(state_abbreviation = '')
        return bothify(fetch('address.postcode')) if state_abbreviation === ''

        # provide a zip code that is valid for the state provided
        # see http://www.fincen.gov/forms/files/us_state_territory_zip_codes.pdf
        bothify(fetch('address.postcode_by_state.' + state_abbreviation))
      end