Verifying a signature raises exception

[azbuky]

Unhandled exception:
Invalid argument(s): Invalid digest length (required: 1 - 64)
#0      new Blake2bDigest (package:pointycastle/digests/blake2b.dart:47:7)
#1      TweetNaclFast.cryptoHashOff (package:nanodart/src/crypto/tweetnacl_blake2b.dart:1576:29)
#2      TweetNaclFast.cryptoSignOpen (package:nanodart/src/crypto/tweetnacl_blake2b.dart:1916:5)
#3      Signature.detachedVerify (package:nanodart/src/crypto/tweetnacl_blake2b.dart:68:27)
...

Sample code

  String seed = NanoSeeds.generateSeed();
  // Getting private key at index-0 of this seed
  String privateKey = NanoKeys.seedToPrivate(seed, 0);
  // Getting public key from this private key
  String pubKey = NanoKeys.createPublicKey(privateKey);
  // Getting address (nano_, ban_) from this pubkey
  String address = NanoAccounts.createAccount(NanoAccountType.NANO, pubKey);
  // Validating address
  NanoAccounts.isValid(NanoAccountType.NANO, address);

  // Creating a block
  int accountType = NanoAccountType.NANO;
  String account =
      'xrb_3igf8hd4sjshoibbbkeitmgkp1o6ug4xads43j6e4gqkj5xk5o83j8ja9php';
  String previous = '0';
  String representative =
      'xrb_3p1asma84n8k84joneka776q4egm5wwru3suho9wjsfyuem8j95b3c78nw8j';
  BigInt balance = BigInt.parse('1');
  String link =
      '1EF0AD02257987B48030CC8D38511D3B2511672F33AF115AD09E18A86A8355A8';
  String calculatedHash = NanoBlocks.computeStateHash(
      accountType, account, previous, representative, balance, link);
  // Signing a block
  final signature = NanoSignatures.signBlock(calculatedHash, privateKey);

  // Check signature
  Signature.detachedVerify(
    NanoHelpers.hexToBytes(calculatedHash),
    NanoHelpers.hexToBytes(signature),
    NanoHelpers.hexToBytes(pubKey),
  );