# File lib/dnsruby/resource/NXT.rb, line 227
    def codes_to_binary_string(codes)
      codes = codes.sort
      unless legal_code_value?(codes.first) && legal_code_value?(codes.last)
        raise ArgumentError.new("All codes must be between 1 and 127: #{codes.inspect}.")
      end
      bitmap_number = BitMapping.set_bit_position_array_to_number(codes)
      BitMapping.number_to_binary_string(bitmap_number)
    end