anchor.diff:  
   
   /**
  - * [HttpBodyHandler] is a helper class for parsing and collecting HTTP message
  - * data in an easy-to-use [HttpBody] object. The content body is parsed,
  - * depending on the 'Content-Type' header field.
  + * [HttpBodyHandler] is a helper class for processing and collecting
  + * HTTP message data in an easy-to-use [HttpBody] object. The content
  + * body is parsed, depending on the `Content-Type` header field. When
  + * the full body is read and parsed the body content is made
  + * available. The class can be used to process both server requests
  + * and client responses.
  + *
  + * The following content types are recognized:
  + *
  + *     text/\*
  + *     application/json
  + *     application/x-www-form-urlencoded
  + *     multipart/form-data
  + *
  + *  For content type `text/\*` the body is decoded into a string. The
  + *  'charset' parameter of the content type specifies the encoding
  + *  used for decoding. If no 'charset' is present the default encoding
  + *  of ISO-8859-1 is used.
  + *
  + *  For content type `application/json` the body is decoded into a
  + *  string which is then parsed as JSON. The resulting body is a
  + *  [Map].  The 'charset' parameter of the content type specifies the
  + *  encoding used for decoding. If no 'charset' is present the default
  + *  encoding of UTF-8 is used.
  + *
  + *  For content type `application/x-www-form-urlencoded` the body is a
  + *  query string which is then split according to the rules for
  + *  splitting a query string. The resulting body is a `Map<String,
  + *  String>`.  If the same name is present several times in the query
  + *  string, then the last value seen for this name will be in the
  + *  resulting map. The encoding US-ASCII is always used for decoding
  + *  the body.
  + *
  + *  For content type `multipart/form-data` the body is parsed into
  + *  it's different fields. The resulting body is a `Map<String,
  + *  dynamic>`, where the value is a [String] for normal fields and a
  + *  [HttpBodyFileUpload] instance for file upload fields. If the same
  + *  name is present several times, then the last value seen for this
  + *  name will be in the resulting map.
  + *
  + *  When using content type `multipart/form-data` the encoding of
  + *  fields with [String] values is determined by the browser sending
  + *  the HTTP request with the form data. The encoding is specified
  + *  either by the attribute `accept-charset` on the HTML form, or by
  + *  the content type of the web page containing the form. If the HTML
  + *  form has an `accept-charset` attribute the browser will use the
  + *  encoding specified there. If the HTML form has no `accept-charset`
  + *  attribute the browser determines the encoding from the content
  + *  type of the web page containing the form. Using a content type of
  + *  `text/html; charset=utf-8` for the page and setting
  + *  `accept-charset` on the HTML form to `utf-8` is recommended as the
  + *  default for [HttpBodyHandler] is UTF-8. It is important to get
  + *  these encoding values right, as the actual `multipart/form-data`
  + *  HTTP request sent by the browser does _not_ contain any
  + *  information on the encoding. If something else than UTF-8 is used
  + *  `defaultEncoding` needs to be set in the [HttpBodyHandler]
  + *  constructor and calls to [processRequest] and [processResponse].
  + *
  + *  For all other content types the body will be treated as
  + *  uninterpreted binary data. The resulting body will be of type
  + *  `List<int>`.
    *
    * To use with the [HttpServer] for request messages, [HttpBodyHandler] can be
    * used as either a [StreamTransformer] or as a per-request handler (see
  
positive.code:  *           ...
   *         });
   *
   * The following mime-types will be handled specially:
   *   - text/\*
   *   - application/json
   *
   * All other mime-types will be returned as [List<int>].
   */
  class HttpBodyHandler
      implements StreamTransformer<HttpRequest, HttpRequestBody> {
  
negative.code:    * Create a new [HttpBodyHandler] to be used with a [Stream]<[HttpRequest]>,
     * e.g. a [HttpServer].
     *
     * If the page is served using different encoding than UTF-8, set
     * [defaultEncoding] accordingly. This is required for parsing
     * `multipart/form-data` content correctly. See the class comment
     * for more information on `multipart/form-data`.
     */
    HttpBodyHandler({Encoding defaultEncoding: Encoding.UTF_8})
        : _transformer = new _HttpBodyHandlerTransformer(defaultEncoding);
  