public static String toString(long n)
public static String toString(byte[] ba)
  public static String toString(long n)  {    char[] b = new char[16];    for (int i = 15; i >= 0; i--)      {        b[i] = HEX_DIGITS[(int) (n & 0x0FL)];        n >>>= 4;      }    return new String(b);  }