code: func getConnectionHash(a, b enode.ID) uint64 {
  	var h [8]byte
  	for i := 0; i < 8; i++ {
  		h[i] = a[i] ^ b[i]
  	}
  	res := binary.LittleEndian.Uint64(h[:])
  	return res
  }
docs: // returns an integer connection identifier (similar to 8-byte hash)