code: function (path, callback) {
      var mkdir = child_process.spawn('mkdir', ['-p', path]);
      mkdir.on('error', function (err) {
          callback(err);
          callback = function(){};
      });
      mkdir.on('exit', function (code) {
          if (code === 0) callback();
          else callback(new Error('mkdir exited with code: ' + code));
      });
  }
docs: Ensures a directory exists using mkdir -p.
  
  @param {String} path
  @param {Function} callback
  @api private