anchor.diff:          false -> not_valid
       end.
   
  --spec record2fix(tuple(), fix_version ()) -> binary() | not_valid.
  +-spec record2fix(tuple(any()), fix_version ()) -> binary() | not_valid.
   record2fix(#custom_message{standardHeader = Header, standardTrailer = Trailer},
              FixVersion) ->
       Utils = get_util_module(FixVersion),
  
positive.code:             lists:sublist(S, L)
      end.
  
  -spec set_msg_seqnum(tuple(), 
                     pos_integer(), 
                     fix_version ()) -> tuple() | not_valid.
  set_msg_seqnum(Record, Num, FixVersion)->
      Utils = get_util_module(FixVersion),
      try
  
negative.code:             completeBinary(Utils, Bin)
      end.
  
  -spec record2fix(FixRecord :: tuple(any()), 
                    ExtraBin :: binary(),
                    fix_version ()) -> binary() | not_valid.
  
  