code: public static void hexToBits(String s, BitSet ba, int length) {
          byte[] b = hexToBytes(s);
          bytesToBits(b, ba, length);
      }
docs: Read a hex string of bits and write it into a bitset
  
  @param s      hex string of the stored bits
  @param ba     the bitset to store the bits in
  @param length the maximum number of bits to store