anchor.diff:          {ok, _Result} ->
               ok;
           {error, Reason} ->
  -            throw(Reason)
  +            {error, Reason}
       end.
   
   -spec collaborators(credentials(), repository()) -> result().
  
positive.code:             JsonResult = jiffy:decode(Result, [return_maps]),
              {ok, JsonResult};
          {error, Reason} ->
              throw(Reason)
      end.
  
  -spec repos(credentials(), string()) -> result().
  
negative.code:             Content = base64:decode(ContentBase64),
              {ok, Content};
          {error, Reason} ->
              {error, Reason}
      end.
  
  -spec user(credentials()) -> result().
  