@SuppressWarnings("unchecked") // safe cast of immutable set
  @Override
  public ImmutableSortedSet<Path> getRootDirectories() {
    ImmutableSortedSet.Builder<JimfsPath> builder = ImmutableSortedSet.orderedBy(pathService);
    for (Name name : fileStore.getRootDirectoryNames()) {
      builder.add(pathService.createRoot(name));
    }
    return (ImmutableSortedSet<Path>) (ImmutableSortedSet<?>) builder.build();
  }
Returns the default view for this file system.
jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystem.java