code: func DecompressPubkey(pubkey []byte) (*ecdsa.PublicKey, error) {
  	x, y := secp256k1.DecompressPubkey(pubkey)
  	if x == nil {
  		return nil, fmt.Errorf("invalid public key")
  	}
  	return &ecdsa.PublicKey{X: x, Y: y, Curve: S256()}, nil
  }
docs: // DecompressPubkey parses a public key in the 33-byte compressed format.