HTTP response to be send back to the client.

abstract class HttpResponse {
  /**
   * Gets and sets the content length of the response. If the size of
   * the response is not known in advance set the content length to
   * -1 - which is also the default if not set.
   */
  int contentLength;

  /**
   * Gets and sets the status code. Any integer value is accepted. For
   * the official HTTP status codes use the fields from
   * [HttpStatus]. If no status code is explicitly set the default
   * value [HttpStatus.OK] is used.
   */
  int statusCode;

  /**
   * Gets and sets the reason phrase. If no reason phrase is explicitly
   * set a default reason phrase is provided.
   */
  String reasonPhrase;

  /**
   * Gets and sets the persistent connection state. The initial value
   * of this property is the persistent connection state from the
   * request.
   */
  bool persistentConnection;

  /**
   * Returns the response headers.
   */
  HttpHeaders get headers;

  /**
   * Cookies to set in the client (in the Set-Cookie header).
   */
  List<Cookie> get cookies;

  /**
   * Returns the output stream for the response. This is used to write
   * the response data. When all response data has been written close
   * the stream to indicate the end of the response.
   *
   * When this is accessed for the first time the response header is
   * send. Calling any methods that will change the header after
   * having retrieved the output stream will throw an exception.
   */
  OutputStream get outputStream;

  /**
   * Detach the underlying socket from the HTTP server. When the
   * socket is detached the HTTP server will no longer perform any
   * operations on it.
   *
   * This is normally used when a HTTP upgrade request is received
   * and the communication should continue with a different protocol.
   */
  DetachedSocket detachSocket();

  /**
   * Get information about the client connection. Returns [null] if the socket
   * isn't available.
   */
  HttpConnectionInfo get connectionInfo;
}