anchor.diff:          orElse: () => '');
   
       var name = 'mastodondartupload${date}_$random_suffix.$ext';
  -    var mpf = new http.MultipartFile.fromBytes('file', media,
  +    var mpf = new MultipartFile.fromBytes('file', media,
           filename: name, contentType: new MediaType.parse(mime_type));
       return DSON.map(
           await _api_request('POST', '/api/v1/media', {}, {'file': mpf}),
  
positive.code: 
  export 'src/mastodon_base.dart';
  
  import 'package:http/http.dart' as http;
  import 'dart:convert';
  import 'dart:io';
  import 'package:mime/mime.dart';
  
negative.code:       var request;
  
        if (files.isEmpty) {
          request = new Request(method, uri);
        } else {
          request = new MultipartRequest(method, uri);
          for (var f in files.keys) {
            await request.files.add(files[f]);
          }
  