code: func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (ccount *Account, _ error) {
  	account, err := ks.keystore.ImportPreSaleKey(common.CopyBytes(keyJSON), passphrase)
  	if err != nil {
  		return nil, err
  	}
  	return &Account{account}, nil
  }
docs: // ImportPreSaleKey decrypts the given Ethereum presale wallet and stores
  // a key file in the key directory. The key file is encrypted with the same passphrase.