anchor.diff:  }
   
   /**
  - * Exit the Dart VM process immediately with the given [status] code.
  + * Exit the Dart VM process immediately with the given exit code.
    *
    * This does not wait for any asynchronous operations to terminate. Using
    * [exit] is therefore very likely to lose data.
  - */
  -void exit(int status) {
  + *
  + * The handling of exit codes is platform specific.
  + *
  + * On Linux and Mac OS an exit code for normal termination will always
  + * be in the range [0..255]. If an exit code outside this range is
  + * set the actual exit code will be the lower 8 bits masked off and
  + * treated as an unsigned value. E.g. using an exit code of -1 will
  + * result in an actual exit code of 255 being reported.
  + *
  + * On Windows the exit code can be set to any 32-bit value. However
  + * some of these values are reserved for reporting system errors like
  + * crashes.
  + *
  + * Besides this the Dart executable itself uses an exit code of `254`
  + * for reporting compile time errors and an exit code of `255` for
  + * reporting runtime error (unhandled exception).
  + *
  + * Due to these facts it is recommended to only use exit codes in the
  + * range [0..127] for communicating the result of running a Dart
  + * program to the surrounding environment. This will avoid any
  + * cross-platform issues.
  + */
  +void exit(int code) {
     if (status is !int) {
       throw new ArgumentError("exit: int status expected");
     }
  
positive.code: 
    /**
     * Returns the standard output stream of the process as a [:Stream:].
     *
     * Throws an [UnsupportedError] if the process is
     * non-interactive.
     */
    Stream<List<int>> get stdout;
  
    /**
     * Returns the standard error stream of the process as a [:Stream:].
     *
     * Throws an [UnsupportedError] if the process is
     * non-interactive.
     */
    Stream<List<int>> get stderr;
  
    /**
     * Returns the standard input stream of the process as an [IOSink].
     *
     * Throws an [UnsupportedError] if the process is
     * non-interactive.
     */
    IOSink get stdin;
  
  
negative.code: abstract class ProcessResult {
    /**
     * Exit code for the process.
     *
     * See [Process.exitCode] for more information in the exit code
     * value.
     */
    int get exitCode;
  
  