@Override
  public FileSystem newFileSystem(Path path, Map<String, ?> env) throws IOException {
    JimfsPath checkedPath = checkPath(path);
    checkNotNull(env);

    URI pathUri = checkedPath.toUri();
    URI jarUri = URI.create("jar:" + pathUri);

    try {
      // pass the new jar:jimfs://... URI to be handled by ZipFileSystemProvider
      return FileSystems.newFileSystem(jarUri, env);
    } catch (Exception e) {
      // if any exception occurred, assume the file wasn't a zip file and that we don't support
      // viewing it as a file system
      throw new UnsupportedOperationException(e);
    }
  }
Returns the singleton instance of this provider.
jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystemProvider.java