anchor.diff:  abstract class ProcessResult {
     /**
      * Exit code for the process.
  +   *
  +   * See [Process.exitCode] for more information in the exit code
  +   * value.
      */
     int get exitCode;
   
  
positive.code: }
  
  /**
   * Exit the Dart VM process immediately with the given [status] code.
   *
   * This does not wait for any asynchronous operations to terminate. Using
   * [exit] is therefore very likely to lose data.
   */
  void exit(int status) {
    if (status is !int) {
      throw new ArgumentError("exit: int status expected");
    }
  
negative.code: 
    /**
     * Returns the standard output stream of the process as a [:Stream:].
     */
    Stream<List<int>> get stdout;
  
    /**
     * Returns the standard error stream of the process as a [:Stream:].
     */
    Stream<List<int>> get stderr;
  
    /**
     * Returns the standard input stream of the process as an [IOSink].
     */
    IOSink get stdin;
  
  