code: func shiftLower(bit byte, b []byte) byte {
  	bit = bit << 7
  	for i := len(b) - 1; i >= 0; i-- {
  		newByte := b[i] >> 1
  		newByte |= bit
  		bit = (b[i] & 1) << 7
  		b[i] = newByte
  	}
  	return bit >> 7
  }
docs: // This function shifts a byte slice one bit lower (less significant).
  // bit (either 1 or 0) contains the bit to put in the most significant
  // position of the last byte in the slice.
  // This returns the bit that was shifted off of the last byte.