private static string CalculateChecksum(string address)
{
ICurl curl = SpongeFactory.Create(SpongeFactory.Mode.KERL);
curl.Reset();
curl.Absorb(Converter.ToTrits(address));
sbyte[] checksumTrits = new sbyte[Sponge.HASH_LENGTH];
curl.Squeeze(checksumTrits);
string checksum = Converter.ToTrytes(checksumTrits);
return(checksum.Substring(72, 9));
}
public void ShouldCreateValidHash1()
{
sbyte[] trits =
Converter.ToTrits("GYOMKVTSNHVJNCNFBBAH9AAMXLPLLLROQY99QN9DLSJUHDPBLCFFAIQXZA9BKMBJCYSFHFPXAHDWZFEIZ");
Kerl kerl = (Kerl)SpongeFactory.Create(SpongeFactory.Mode.KERL);
kerl.Reset();
kerl.Absorb(trits, 0, trits.Length);
sbyte[] hashTrits = new sbyte[trits.Length];
kerl.Squeeze(hashTrits, 0, 243);
string hash = Converter.ToTrytes(hashTrits);
Assert.AreEqual(hash, "OXJCNFHUNAHWDLKKPELTBFUCVW9KLXKOGWERKTJXQMXTKFKNWNNXYD9DMJJABSEIONOSJTTEVKVDQEWTW");
}
public void ShouldCreateValidHash2()
{
sbyte[] trits =
Converter.ToTrits("9MIDYNHBWMBCXVDEFOFWINXTERALUKYYPPHKP9JJFGJEIUY9MUDVNFZHMMWZUYUSWAIOWEVTHNWMHANBH");
Kerl kerl = (Kerl)SpongeFactory.Create(SpongeFactory.Mode.KERL);
kerl.Reset();
kerl.Absorb(trits, 0, trits.Length);
sbyte[] hashTrits = new sbyte[trits.Length * 2];
kerl.Squeeze(hashTrits, 0, 243 * 2);
string hash = Converter.ToTrytes(hashTrits);
Assert.AreEqual(hash,
"G9JYBOMPUXHYHKSNRNMMSSZCSHOFYOYNZRSZMAAYWDYEIMVVOGKPJBVBM9TDPULSFUNMTVXRKFIDOHUXXVYDLFSZYZTWQYTE9SPYYWYTXJYQ9IFGYOLZXWZBKWZN9QOOTBQMWMUBLEWUEEASRHRTNIQWJQNDWRYLCA");
}
public void ShouldCreateValidHash3()
{
sbyte[] trits =
Converter.ToTrits(
"G9JYBOMPUXHYHKSNRNMMSSZCSHOFYOYNZRSZMAAYWDYEIMVVOGKPJBVBM9TDPULSFUNMTVXRKFIDOHUXXVYDLFSZYZTWQYTE9SPYYWYTXJYQ9IFGYOLZXWZBKWZN9QOOTBQMWMUBLEWUEEASRHRTNIQWJQNDWRYLCA");
Kerl kerl = (Kerl)SpongeFactory.Create(SpongeFactory.Mode.KERL);
kerl.Reset();
kerl.Absorb(trits, 0, trits.Length);
sbyte[] hashTrits = new sbyte[trits.Length];
kerl.Squeeze(hashTrits, 0, 243 * 2);
string hash = Converter.ToTrytes(hashTrits);
Assert.AreEqual(hash,
"LUCKQVACOGBFYSPPVSSOXJEKNSQQRQKPZC9NXFSMQNRQCGGUL9OHVVKBDSKEQEBKXRNUJSRXYVHJTXBPDWQGNSCDCBAIRHAQCOWZEBSNHIJIGPZQITIBJQ9LNTDIBTCQ9EUWKHFLGFUVGGUWJONK9GBCDUIMAYMMQX");
}
private string GetFirstUnusedAddress(string seed, int securityLevel, int index, bool checksum)
{
while (true)
{
string newAddress =
IotaApiUtils.NewAddress(
seed, securityLevel, index, checksum,
SpongeFactory.Create(SpongeFactory.Mode.KERL));
if (!IsAddressSpent(newAddress, checksum))
{
return(newAddress);
}
index++;
}
}
public void TestLongSeedKeyGeneration()
{
ICurl curl = SpongeFactory.Create(SpongeFactory.Mode.KERL);
Signing signing = new Signing(curl);
string seed = "EV9QRJFJZVFNLYUFXWKXMCRRPNAZYQVEYB9VEPUHQNXJCWKZFVUCTQJFCUAMXAHMMIUQUJDG9UGGQBPIY";
for (int i = Constants.MIN_SECURITY_LEVEL; i < Constants.MAX_SECURITY_LEVEL; i++)
{
sbyte[] key1 = signing.Key(Converter.ToTrits(seed), 0, i);
Assert.AreEqual(Constants.KEY_LENGTH * i, key1.Length);
sbyte[] key2 = signing.Key(Converter.ToTrits(seed + seed), 0, i);
Assert.AreEqual(Constants.KEY_LENGTH * i, key2.Length);
sbyte[] key3 = signing.Key(Converter.ToTrits(seed + seed + seed), 0, i);
Assert.AreEqual(Constants.KEY_LENGTH * i, key3.Length);
}
}
private List <string> GetAddresses(string seed, int securityLevel, int index, bool checksum, int amount,
bool addSpendAddresses)
{
List <string> addresses = new List <string>();
for (int i = index, numUnspentFound = 0; numUnspentFound < amount; i++)
{
string newAddress = IotaApiUtils.NewAddress(seed, securityLevel, i, checksum,
SpongeFactory.Create(SpongeFactory.Mode.KERL));
if (!IsAddressSpent(newAddress, checksum))
{
addresses.Add(newAddress);
numUnspentFound++;
}
else if (addSpendAddresses)
{
addresses.Add(newAddress);
}
}
return(addresses);
}
/// <summary>
/// This does not mean that these addresses are safe to use (unspent)
/// </summary>
/// <param name="addressRequest"></param>
/// <returns></returns>
public GetNewAddressResponse GetAddressesUnchecked(AddressRequest addressRequest)
{
var stopwatch = Stopwatch.StartNew();
List <string> addresses = new List <string>();
for (int i = 0; i < addressRequest.Amount; i++)
{
addresses.Add(
IotaApiUtils.NewAddress(
addressRequest.Seed,
addressRequest.SecurityLevel, i,
addressRequest.Checksum,
SpongeFactory.Create(SpongeFactory.Mode.KERL)));
}
stopwatch.Stop();
return(new GetNewAddressResponse
{
Addresses = addresses,
Duration = stopwatch.ElapsedMilliseconds
});
}
/// <summary>
///
/// </summary>
/// <param name="seed"></param>
/// <param name="security"></param>
/// <param name="transfers"></param>
/// <param name="remainder"></param>
/// <param name="inputs"></param>
/// <param name="tips"></param>
/// <param name="validateInputs"></param>
/// <returns></returns>
public List <string> PrepareTransfers(
string seed, int security,
Transfer[] transfers,
string remainder,
Input[] inputs,
Transaction[] tips,
bool validateInputs)
{
// validate seed
if (!InputValidator.IsValidSeed(seed))
{
throw new IllegalStateException(Constants.INVALID_SEED_INPUT_ERROR);
}
if (!InputValidator.IsValidSecurityLevel(security))
{
throw new ArgumentException(Constants.INVALID_SECURITY_LEVEL_INPUT_ERROR);
}
if (remainder != null && !InputValidator.IsAddress(remainder))
{
throw new ArgumentException(Constants.INVALID_ADDRESSES_INPUT_ERROR);
}
// Input validation of transfers object
if (!InputValidator.IsValidTransfersCollection(transfers.ToList()))
{
throw new ArgumentException(Constants.INVALID_TRANSFERS_INPUT_ERROR);
}
if (inputs != null && !InputValidator.IsValidInputsCollection(inputs))
{
throw new ArgumentException(Constants.INVALID_ADDRESSES_INPUT_ERROR);
}
// Create a new bundle
var bundle = new Bundle();
var signatureFragments = new List <string>();
long totalValue = 0;
var tag = "";
//
// Iterate over all transfers, get totalValue
// and prepare the signatureFragments, message and tag
//
foreach (var transfer in transfers)
{
// remove the checksum of the address if provided
transfer.Address = transfer.Address.RemoveChecksum();
var signatureMessageLength = 1;
// If message longer than 2187 trytes, increase signatureMessageLength (add 2nd transaction)
if (transfer.Message.Length > Constants.MESSAGE_LENGTH)
{
// Get total length, message / maxLength (2187 trytes)
signatureMessageLength +=
(int)Math.Floor((double)transfer.Message.Length / Constants.MESSAGE_LENGTH);
var msgCopy = transfer.Message;
// While there is still a message, copy it
while (!string.IsNullOrEmpty(msgCopy))
{
var fragment = msgCopy.Substring(0, 2187 > msgCopy.Length ? msgCopy.Length : 2187);
msgCopy = msgCopy.Substring(fragment.Length, msgCopy.Length - fragment.Length);
// Pad remainder of fragment
if (fragment.Length < 2187)
{
fragment = fragment.PadRight(2187, '9');
}
signatureFragments.Add(fragment);
}
}
else
{
// Else, get single fragment with 2187 of 9's trytes
var fragment = transfer.Message.PadRight(Constants.MESSAGE_LENGTH, '9');
signatureFragments.Add(fragment);
}
// get current timestamp in seconds
var timestamp = (long)Math.Floor((double)TimeStamp.Now() / 1000);
// If no tag defined, get 27 tryte tag.
tag = string.IsNullOrEmpty(transfer.Tag) ? "999999999999999999999999999" : transfer.Tag;
// Pad for required 27 tryte length
if (tag.Length < Constants.TAG_LENGTH)
{
tag = tag.PadRight(Constants.TAG_LENGTH, '9');
}
// Add first entries to the bundle
// Slice the address in case the user provided a checksummed one
bundle.AddEntry(signatureMessageLength, transfer.Address, transfer.Value, tag, timestamp);
// Sum up total value
totalValue += transfer.Value;
}
// Get inputs if we are sending tokens
if (totalValue != 0)
{
// validate seed
if (!InputValidator.IsValidSeed(seed))
{
throw new IllegalStateException(Constants.INVALID_SEED_INPUT_ERROR);
}
// Case 1: user provided inputs
// Validate the inputs by calling getBalances
if (inputs != null && inputs.Length > 0)
{
if (!validateInputs)
{
return(AddRemainder(seed, security, inputs.ToList(), bundle, tag, totalValue, remainder,
signatureFragments));
}
// Get list if addresses of the provided inputs
var inputAddresses = new List <string>();
foreach (var input in inputs)
{
inputAddresses.Add(input.Address);
}
List <string> tipHashes = null;
if (tips != null)
{
tipHashes = new List <string>();
foreach (var tx in tips)
{
tipHashes.Add(tx.CurlHash());
}
}
var balances = IotaClient.GetBalances(100, inputAddresses, tipHashes);
var confirmedInputs = new List <Input>();
long totalBalance = 0;
for (var i = 0; i < balances.Balances.Count; i++)
{
var thisBalance = balances.Balances[i];
totalBalance += thisBalance;
// If input has balance, add it to confirmedInputs
if (thisBalance > 0)
{
var inputEl = inputs[i];
inputEl.Balance = thisBalance;
confirmedInputs.Add(inputEl);
// if we've already reached the intended input value, break out of loop
if (totalBalance >= totalValue)
{
Log.Info("Total balance already reached ");
break;
}
}
}
// Return not enough balance error
if (totalValue > totalBalance)
{
throw new IllegalStateException(Constants.NOT_ENOUGH_BALANCE_ERROR);
}
return(AddRemainder(seed, security, confirmedInputs, bundle, tag, totalValue, remainder,
signatureFragments));
}
// Case 2: Get inputs deterministically
//
// If no inputs provided, derive the addresses from the seed and
// confirm that the inputs exceed the threshold
var inputList = GetInputs(seed, security, 0, 0, (int)totalValue).Inputs;
return(AddRemainder(seed, security, inputList, bundle, tag, totalValue, remainder,
signatureFragments));
}
// If no input required, don't sign and simply finalize the bundle
bundle.FinalizeBundle(SpongeFactory.Create(SpongeFactory.Mode.KERL));
bundle.AddTrytes(signatureFragments);
var bundleTrytes = new List <string>();
bundle.Transactions.ForEach(tx => bundleTrytes.Add(tx.ToTrytes()));
bundleTrytes.Reverse();
return(bundleTrytes);
}
private List <string> AddRemainder(
string seed,
int security,
List <Input> inputs,
Bundle bundle,
string tag,
long totalValue,
string remainderAddress,
List <string> signatureFragments)
{
var totalTransferValue = totalValue;
foreach (var input in inputs)
{
var thisBalance = input.Balance;
var toSubtract = 0 - thisBalance;
var timestamp = TimeStamp.Now();
// Add input as bundle entry
// use input.Security
bundle.AddEntry(input.Security, input.Address, toSubtract, tag, timestamp);
// If there is a remainder value
// Add extra output to send remaining funds to
if (thisBalance >= totalTransferValue)
{
var remainder = thisBalance - totalTransferValue;
// If user has provided remainder address
// Use it to send remaining funds to
if (remainder > 0 && remainderAddress != null)
{
// Remainder bundle entry
bundle.AddEntry(1, remainderAddress, remainder, tag, timestamp);
// function for signing inputs
return(IotaApiUtils.SignInputsAndReturn(
seed, inputs, bundle, signatureFragments,
SpongeFactory.Create(SpongeFactory.Mode.KERL)));
}
if (remainder > 0)
{
AddressRequest addressRequest = new AddressRequest(seed, security);
var res = GenerateNewAddresses(addressRequest);
// Remainder bundle entry
bundle.AddEntry(1, res.Addresses[0], remainder, tag, timestamp);
// function for signing inputs
return(IotaApiUtils.SignInputsAndReturn(
seed, inputs, bundle, signatureFragments,
SpongeFactory.Create(SpongeFactory.Mode.KERL)));
}
// If there is no remainder, do not add transaction to bundle
// simply sign and return
return(IotaApiUtils.SignInputsAndReturn(
seed, inputs, bundle, signatureFragments,
SpongeFactory.Create(SpongeFactory.Mode.KERL)));
}
// If multiple inputs provided, subtract the totalTransferValue by
// the inputs balance
totalTransferValue -= thisBalance;
}
throw new IllegalStateException(Constants.NOT_ENOUGH_BALANCE_ERROR);
}
/// <summary>
///
/// </summary>
/// <param name="securitySum"></param>
/// <param name="inputAddress"></param>
/// <param name="remainderAddress"></param>
/// <param name="transfers"></param>
/// <param name="tips"></param>
/// <param name="testMode"></param>
/// <returns></returns>
public List <Transaction> InitiateTransfer(
int securitySum, string inputAddress, string remainderAddress,
List <Transfer> transfers, List <Transaction> tips, bool testMode)
{
// validate input address
if (!InputValidator.IsAddress(inputAddress))
{
throw new ArgumentException("Invalid addresses provided.");
}
// validate remainder address
if (remainderAddress != null && !InputValidator.IsAddress(remainderAddress))
{
throw new ArgumentException("Invalid addresses provided.");
}
// Input validation of transfers object
if (!InputValidator.IsValidTransfersCollection(transfers))
{
throw new ArgumentException("Invalid transfers provided.");
}
// Create a new bundle
Bundle bundle = new Bundle();
long totalValue = 0;
List <String> signatureFragments = new List <string>();
String tag = "";
//
// Iterate over all transfers, get totalValue
// and prepare the signatureFragments, message and tag
foreach (Transfer transfer in transfers)
{
// remove the checksum of the address if provided
if (transfer.Address.IsValidChecksum())
{
transfer.Address = transfer.Address.RemoveChecksum();
}
int signatureMessageLength = 1;
// If message longer than 2187 trytes, increase signatureMessageLength (add next transaction)
if (transfer.Message.Length > Constants.MESSAGE_LENGTH)
{
// Get total length, message / maxLength (2187 trytes)
signatureMessageLength +=
(int)Math.Floor((double)transfer.Message.Length / Constants.MESSAGE_LENGTH);
String msgCopy = transfer.Message;
// While there is still a message, copy it
while (!string.IsNullOrEmpty(msgCopy))
{
string fragment = msgCopy.Substring(0, Constants.MESSAGE_LENGTH);
msgCopy = msgCopy.Substring(Constants.MESSAGE_LENGTH,
msgCopy.Length - Constants.MESSAGE_LENGTH);
// Pad remainder of fragment
fragment = fragment.PadRight(Constants.MESSAGE_LENGTH, '9');
signatureFragments.Add(fragment);
}
}
else
{
// Else, get single fragment with 2187 of 9's trytes
String fragment = transfer.Message;
if (transfer.Message.Length < Constants.MESSAGE_LENGTH)
{
fragment = fragment.PadRight(Constants.MESSAGE_LENGTH, '9');
}
signatureFragments.Add(fragment);
}
tag = transfer.Tag;
// pad for required 27 tryte length
if (transfer.Tag.Length < Constants.TAG_LENGTH)
{
tag = tag.PadRight(Constants.TAG_LENGTH, '9');
}
// get current timestamp in seconds
long timestamp = (long)Math.Floor(GetCurrentTimestampInSeconds());
// Add first entry to the bundle
bundle.AddEntry(signatureMessageLength, transfer.Address, transfer.Value, tag, timestamp);
// Sum up total value
totalValue += transfer.Value;
}
// Get inputs if we are sending tokens
if (totalValue != 0)
{
List <string> tipHashes = null;
if (tips != null)
{
tipHashes = new List <string>();
foreach (var tx in tips)
{
tipHashes.Add(tx.CurlHash());
}
}
GetBalancesResponse balancesResponse =
IotaClient.GetBalances(100, new List <string> {
inputAddress
}, tipHashes);
var balances = balancesResponse.Balances;
long totalBalance = 0;
foreach (var balance in balances)
{
totalBalance += balance;
}
// get current timestamp in seconds
long timestamp = (long)Math.Floor(GetCurrentTimestampInSeconds());
// bypass the balance checks during unit testing
//TODO remove this ugliness
if (testMode)
{
totalBalance += 1000;
}
if (totalBalance > 0)
{
long toSubtract = 0 - totalBalance;
// Add input as bundle entry
// Only a single entry, signatures will be added later
bundle.AddEntry(securitySum, inputAddress, toSubtract, tag, timestamp);
}
// Return not enough balance error
if (totalValue > totalBalance)
{
throw new IllegalStateException("Not enough balance.");
}
// If there is a remainder value
// Add extra output to send remaining funds to
if (totalBalance > totalValue)
{
long remainder = totalBalance - totalValue;
// Remainder bundle entry if necessary
if (remainderAddress == null)
{
throw new IllegalStateException("No remainder address defined.");
}
bundle.AddEntry(1, remainderAddress, remainder, tag, timestamp);
}
bundle.FinalizeBundle(SpongeFactory.Create(SpongeFactory.Mode.CURLP81));
bundle.AddTrytes(signatureFragments);
return(bundle.Transactions);
}
else
{
throw new System.Exception("Invalid value transfer: the transfer does not require a signature.");
}
}
/// <summary>
///
/// </summary>
/// <param name="seed"></param>
/// <param name="security"></param>
/// <param name="start"></param>
/// <param name="end"></param>
/// <param name="threshold"></param>
/// <param name="tips"></param>
/// <returns></returns>
public GetBalancesAndFormatResponse GetInputs(string seed, int security, int start, int end, long threshold,
params string[] tips)
{
// validate the seed
if (!InputValidator.IsValidSeed(seed))
{
throw new IllegalStateException(Constants.INVALID_SEED_INPUT_ERROR);
}
seed = InputValidator.PadSeedIfNecessary(seed);
if (!InputValidator.IsValidSecurityLevel(security))
{
throw new ArgumentException(Constants.INVALID_SECURITY_LEVEL_INPUT_ERROR);
}
// If start value bigger than end, return error
if (start > end)
{
throw new ArgumentException("start must be smaller than end", nameof(start));
}
// or if difference between end and start is bigger than 500 keys
if (end - start > 500)
{
throw new ArgumentException("total number of keys exceeded 500");
}
Stopwatch stopwatch = Stopwatch.StartNew();
// Case 1: start and end
//
// If start and end is defined by the user, simply iterate through the keys
// and call getBalances
if (end != 0)
{
var allAddresses = new string[end - start];
for (var i = start; i < end; i++)
{
var address = IotaApiUtils.NewAddress(seed, security, i, true,
SpongeFactory.Create(SpongeFactory.Mode.KERL));
allAddresses[i] = address;
}
return(GetBalanceAndFormat(allAddresses, tips, threshold, start, security, stopwatch));
}
{
// Case 2: iterate till threshold
//
// Either start from index: 0 or start (if defined) until threshold is reached.
List <Input> allInputs = new List <Input>();
bool thresholdReached = true;
long currentTotal = 0;
for (int i = start; thresholdReached; i++)
{
string address = IotaApiUtils.NewAddress(seed, security, i, true,
SpongeFactory.Create(SpongeFactory.Mode.KERL));
// Received input, this epoch or previous
GetBalancesResponse response =
IotaClient.GetBalances(100, new List <string>()
{
address
}, tips.ToList());
var balance = response.Balances[0];
if (balance > 0)
{
// Is it already spent from?
WereAddressesSpentFromResponse wasSpent = IotaClient.WereAddressesSpentFrom(address);
if (wasSpent.States.Length > 0 && !wasSpent.States[0])
{
// We can use this!
allInputs.Add(new Input
{
Address = address, Balance = balance, KeyIndex = i, Security = security
});
currentTotal += balance;
if (threshold != 0 && threshold <= currentTotal)
{
// Stop because we found threshold
thresholdReached = false;
}
}
}
else
{
// Check if there was any activity at all
FindTransactionsResponse tx = IotaClient.FindTransactionsByAddresses(address);
if (tx.Hashes.Count == 0 || i - start > 500)
{
// Stop because we reached our limit or no activity
thresholdReached = false;
}
}
}
stopwatch.Stop();
return(new GetBalancesAndFormatResponse(allInputs, currentTotal, stopwatch.ElapsedMilliseconds));
}
}
public static TransactionViewModel Validate(int[] trits, int minWeightMagnitude)
{
TransactionViewModel transactionViewModel = new TransactionViewModel(trits,
Hash.Calculate(trits, 0, trits.Length, SpongeFactory.Create(SpongeFactory.Mode.CurlP81)));
RunValidation(transactionViewModel, minWeightMagnitude);
return(transactionViewModel);
}
/// <summary>
///
/// </summary>
/// <param name="bundle"></param>
/// <param name="curl"></param>
/// <returns></returns>
public static bool IsBundle(Bundle bundle, ICurl curl = null)
{
if (curl == null)
{
curl = SpongeFactory.Create(SpongeFactory.Mode.KERL);
}
long totalSum = 0;
int lastIndex = bundle.Length - 1;
for (int i = 0; i < bundle.Length; i++)
{
var tx = bundle.Transactions[i];
totalSum += tx.Value;
if (tx.CurrentIndex != i)
{
throw new ArgumentException(Constants.INVALID_BUNDLE_ERROR);
}
if (tx.LastIndex != lastIndex)
{
throw new ArgumentException(Constants.INVALID_BUNDLE_ERROR);
}
sbyte[] txTrits = Converter.ToTrits(tx.ToTrytes().Substring(2187, 162));
curl.Absorb(txTrits);
// continue if output or signature tx
if (tx.Value >= 0)
{
continue;
}
// here we have an input transaction (negative value)
List <string> fragments = new List <string> {
tx.SignatureMessageFragment
};
// find the subsequent txs containing the remaining signature
// message fragments for this input transaction
for (int j = i; j < bundle.Length - 1; j++)
{
Transaction tx2 = bundle.Transactions[j + 1];
// check if the tx is part of the input transaction
if (tx.Address.Equals(tx2.Address, StringComparison.Ordinal) && tx2.Value == 0)
{
// append the signature message fragment
fragments.Add(tx2.SignatureMessageFragment);
}
}
bool valid = new Signing(curl.Clone()).ValidateSignatures(tx.Address, fragments.ToArray(), tx.Bundle);
if (!valid)
{
throw new ArgumentException(Constants.INVALID_SIGNATURES_ERROR);
}
}
// sum of all transaction must be 0
if (totalSum != 0)
{
throw new ArgumentException(Constants.INVALID_BUNDLE_SUM_ERROR);
}
sbyte[] bundleHashTrits = new sbyte[Sponge.HASH_LENGTH];
curl.Squeeze(bundleHashTrits, 0, Sponge.HASH_LENGTH);
string bundleHash = Converter.ToTrytes(bundleHashTrits);
if (!bundleHash.Equals(bundle.Transactions[0].Bundle, StringComparison.Ordinal))
{
throw new ArgumentException(Constants.INVALID_BUNDLE_HASH_ERROR);
}
return(true);
}