anchor.diff:   * Use [bindSecure] to create an HTTPS server.
    *
    * The server presents a certificate to the client. In the following
  - * example, the certificate is named `localhost_cert` and comes from 
  + * example, the certificate is named `localhost_cert` and comes from
    * the database found in the `pkcert` directory.
  - * 
  + *
    *     import 'dart:io';
    *     import "dart:isolate";
    *
  
positive.code:  */
  abstract class HttpServer implements Stream<HttpRequest> {
    /**
     * Set and get the default value of the `Server` header for all responses
     * generated by this [HttpServer]. By default, it's disabled.
     *
     * If the serverHeader is set to `null`, no default `Server` header will be
     * added to each response.
     */
    String serverHeader;
  
  
negative.code:  * The server sends its response to the client by writing to the
   * HttpResponse object.
   *
   * ## Writing the response
   *
   * This class implements [IOSink].
   * After the header has been set up, the methods
  