code: func EncodeCompactBytes(b []byte, data []byte) []byte {
  	b = reallocBytes(b, binary.MaxVarintLen64+len(data))
  	b = EncodeVarint(b, int64(len(data)))
  	return append(b, data...)
  }
docs: // EncodeCompactBytes joins bytes with its length into a byte slice. It is more
  // efficient in both space and time compare to EncodeBytes. Note that the encoded
  // result is not memcomparable.