code: @Deprecated
    public static FileSystem getProxiedFileSystemUsingToken(@NonNull final String userNameToProxyAs,
        final Token<?> userNameToken, final URI fsURI, final Configuration conf) throws ExecutionException {
      try {
        return getProxiedFileSystemUsingToken(userNameToProxyAs, userNameToken, fsURI, conf, null);
      } catch (IOException ioe) {
        throw new ExecutionException(ioe);
      }
    }
docs: Cached version of {@link ProxiedFileSystemUtils#createProxiedFileSystemUsingToken(String, Token, URI, Configuration)}.
  @deprecated use {@link #fromToken}.