anchor.diff:    /// constraints.html#multipart-form-data).
     static HttpMultipartFormData parse(MimeMultipart multipart,
         {Encoding defaultEncoding = utf8}) {
  -    ContentType type;
  +    ContentType contentType;
       HeaderValue encoding;
       HeaderValue disposition;
  -    var remaining = <String, String>{};
       for (var key in multipart.headers.keys) {
         switch (key) {
           case 'content-type':
  -          type = ContentType.parse(multipart.headers[key]);
  +          contentType = ContentType.parse(multipart.headers[key]);
             break;
   
           case 'content-transfer-encoding':
  
positive.code:       throw const HttpException(
            "Mime Multipart doesn't contain a Content-Disposition header value");
      }
      return HttpMultipartFormData._(
          type, disposition, encoding, multipart, defaultEncoding);
    }
  
    final MimeMultipart _mimeMultipart;
  
    Stream _stream;
  
    HttpMultipartFormData._(
        this.contentType,
        this.contentDisposition,
        this.contentTransferEncoding,
        this._mimeMultipart,
        Encoding defaultEncoding) {
      _stream = _mimeMultipart;
      if (contentTransferEncoding != null &&
          !_transparentEncodings
              .contains(contentTransferEncoding.value.toLowerCase())) {
        // TODO(ajohnsen): Support BASE64, etc.
        throw HttpException('Unsupported contentTransferEncoding: '
            '${contentTransferEncoding.value}');
      }
  
      if (contentType == null ||
          contentType.primaryType == 'text' ||
          contentType.mimeType == 'application/json') {
        _isText = true;
        Encoding encoding;
        if (contentType != null && contentType.charset != null) {
          encoding = Encoding.getByName(contentType.charset);
        }
        encoding ??= defaultEncoding;
        _stream = _stream.transform(encoding.decoder);
      }
    }
  
    @override
    StreamSubscription listen(void Function(dynamic) onData,
  
negative.code:           break;
  
          default:
            break;
        }
      }
  