anchor.diff:    Value = <<Priority:16, Hostname/binary>>,
     {Value, byte_size(Value)}.
   
  +%% Convert SOA record data to {binary-representation,length} pair.
   soa_rdata(Rdata) ->
     [MnameStr, RnameStr, SerialStr, RefreshStr, RetryStr, ExpireStr, MinimumStr] = string:tokens(Rdata, " "),
     Mname = string_to_domain_name(MnameStr),
  
positive.code:   {Minimum, _} = string:to_integer(MinimumStr),
    Value = <<Mname/binary, Rname/binary, Serial:32, Refresh:32, Retry:32, Expire:32, Minimum:32>>,
    {Value, byte_size(Value)}.
  
  %% Convert a string to its binary representation.
  string_to_domain_name(String) ->
  
negative.code:   Value = <<TxtLen:8, Txt/binary>>,
    {Value, byte_size(Value)}.
  
  %% Convert record data for MX records to {binary-representation,length} pair.
  mx_rdata(Rdata) ->
    [PriorityStr, HostnameStr] = string:tokens(Rdata, " "),
    {Priority, _} = string:to_integer(PriorityStr),
  