anchor.diff:   * [Directory]. Returns a [Future] that completes when the deletion is done.
    */
   Future<Directory> deleteDir(dir) {
  -  // TODO(rnystrom): Hack! Temporary! Right now, dart:io's Directory delete
  -  // method can't handle directories with symlinks, which is exactly what pub
  -  // creates and deletes. Instead, we'll just shell out to 'rm'. Remove this
  -  // when dartbug.com/2646 is fixed.
  -  dir = _getDirectory(dir);
  -
  -  // Sanity check!
  -  if (dir.path == '/' ||
  -      dir.path == '.' ||
  -      dir.path == '..' ||
  -      dir.path == '~' ||
  -      dir.path == '*') throw "(O.o) I don't think you want to do that!";
  -
  -  return runProcess('rm', ['-rf', dir.path]).transform((_) => dir);
  -  // End hack!
  -
  -  // Real code:
  -  /*
     final completer = new Completer<Directory>();
     dir = _getDirectory(dir);
     dir.onError = (error) => completer.completeException(error);
     dir.deleteRecursively(() => completer.complete(dir));
   
     return completer.future;
  -  */
   }
   
   /**
  
positive.code:  * the result.
   */
  Future<bool> fileExists(file) {
    // TODO(nweiz): Currently File#exists will not detect the existence of
    // symlinks. Issue 2765
    return runProcess('stat', [_getPath(file)]).
      transform((result) => result.exitCode == 0);
  
    // Real code:
    /*
    final completer = new Completer<bool>();
  
    file = new File(_getPath(file));
  
negative.code:   file.exists((exists) => completer.complete(exists));
  
    return completer.future;
  }
  
  /**
  