code: function(){
              // file mode defined ?
              if (mode){
                  // set mode of destination file
                  _fs.chmod(destinationFilename, mode, function(err){
                      if (err){
                          reject(err);
                      }else{
                          resolve();
                      }
                  });
              }else{
                  // finish
                  resolve();
              }
          }
docs: on complete - chmod