code: public static final String bytesToHex(byte[] bs, int off, int length) {
  		StringBuffer sb = new StringBuffer(length * 2);
  		bytesToHexAppend(bs, off, length, sb);
  		return sb.toString();
  	}
docs: Converts a byte array into a string of upper case hex chars.
  
  @param bs
  A byte array
  @param off
  The index of the first byte to read
  @param length
  The number of bytes to read.
  @return the string of hex chars.