// InsertPreState populates the given database with the genesis
// accounts defined by the test.
func (t *BlockTest) InsertPreState(ethereum *eth.Ethereum) (*state.StateDB, error) {
	db := ethereum.StateDb()
	statedb := state.New(common.Hash{}, db)
	for addrString, acct := range t.preAccounts {
		addr, err := hex.DecodeString(addrString)
		if err != nil {
			return nil, err
		}
		code, err := hex.DecodeString(strings.TrimPrefix(acct.Code, "0x"))
		if err != nil {
			return nil, err
		}
		balance, ok := new(big.Int).SetString(acct.Balance, 0)
		if !ok {
			return nil, err
		}
		nonce, err := strconv.ParseUint(prepInt(16, acct.Nonce), 16, 64)
		if err != nil {
			return nil, err
		}

		if acct.PrivateKey != "" {
			privkey, err := hex.DecodeString(strings.TrimPrefix(acct.PrivateKey, "0x"))
			err = crypto.ImportBlockTestKey(privkey)
			err = ethereum.AccountManager().TimedUnlock(common.BytesToAddress(addr), "", 999999*time.Second)
			if err != nil {
				return nil, err
			}
		}

		obj := statedb.CreateAccount(common.HexToAddress(addrString))
		obj.SetCode(code)
		obj.SetBalance(balance)
		obj.SetNonce(nonce)
		for k, v := range acct.Storage {
			statedb.SetState(common.HexToAddress(addrString), common.HexToHash(k), common.HexToHash(v))
		}
	}
	// sync objects to trie
	statedb.SyncObjects()
	// sync trie to disk
	statedb.Sync()

	if !bytes.Equal(t.Genesis.Root().Bytes(), statedb.Root().Bytes()) {
		return nil, fmt.Errorf("computed state root does not match genesis block %x %x", t.Genesis.Root().Bytes()[:4], statedb.Root().Bytes()[:4])
	}
	return statedb, nil
}