code: @Deprecated
    public static FileSystem getProxiedFileSystem(@NonNull final String userNameToProxyAs, Properties properties,
        URI fsURI) throws IOException {
      return getProxiedFileSystem(userNameToProxyAs, properties, fsURI, new Configuration());
    }
docs: Gets a {@link FileSystem} that can perform any operations allowed by the specified userNameToProxyAs.
  
  @param userNameToProxyAs The name of the user the super user should proxy as
  @param properties {@link java.util.Properties} containing initialization properties.
  @param fsURI The {@link URI} for the {@link FileSystem} that should be created.
  @return a {@link FileSystem} that can execute commands on behalf of the specified userNameToProxyAs
  @throws IOException
  @deprecated use {@link #fromProperties}