anchor.diff:  fields_tree(Fields, Opts) ->
       case get_field_format_by_opts(Opts) of
           fields_as_records   ->
  -            erl_syntax:list([field_tree(Field) || Field <- Fields]);
  +            erl_syntax:list([field_tree(Field, Opts) || Field <- Fields]);
           fields_as_proplists ->
               erl_parse:abstract(gpb:field_records_to_proplists(Fields))
       end.
  
positive.code:                     lists:nth(RNum - 1, Params);
                  pass_as_record ->
                      MsgVar = hd(Params),
                      record_access(MsgVar, MsgName, FName)
              end,
      OutParams = case get_field_pass(MsgName, AnRes) of
                      pass_as_params ->
                          lists_setelement(RNum - 1, Params, ?expr(NewSeq));
                      pass_as_record ->
                          [record_update(hd(Params), MsgName,
                                         [{FName, ?expr(NewSeq)}])]
                  end,
      [gpb_codegen:format_fn(
         mk_fn(d_field_, MsgName, FName),
  
negative.code: %%   <dd>Enables `::Type()' annotations in the generated .hrl file.</dd>
  %%   <dt>`-descr'</dt>
  %%   <dd>Generate self-description information.</dd>
  %%   <dt>`-maps'</dt>
  %%   <dd>Generate code that will accept and produce maps instead of
  %%       records. No .hrl file will be generated. See the `maps' option
  %%       for the function {@link file/2} for more info.</dd>
  %%   <dt>`--help' or `-h'</dt>
  %%   <dd>Show help.</dd>
  %%   <dt>`--version' or `-V'</dt>
  