@Override
  public void createDirectory(Path dir, FileAttribute<?>... attrs) throws IOException {
    JimfsPath checkedPath = checkPath(dir);
    FileSystemView view = getDefaultView(checkedPath);
    view.createDirectory(checkedPath, attrs);
  }
Returns the default file system view for the given path.
jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystemProvider.java