code: func (b IPv6Fragment) Encode(i *IPv6FragmentFields) {
  	b[nextHdrFrag] = i.NextHeader
  	binary.BigEndian.PutUint16(b[fragOff:], i.FragmentOffset<<3)
  	if i.M {
  		b[more] |= 1
  	}
  	binary.BigEndian.PutUint32(b[idV6:], i.Identification)
  }
docs: // Encode encodes all the fields of the ipv6 fragment.