CalculateAndSetFee relies on TransactionWitnessSet to be initialized

[nothingalike]

cardanosharp-wallet/CardanoSharp.Wallet/Extensions/Models/Transactions/TransactionExtensions.cs

Line 107 in 5a0794f

transaction.TransactionWitnessSet.VKeyWitnesses.CreateMocks(numberOfVKeyWitnessesToMock);

Found a situation where a transaction is intending to calculate with no witnesses and only mocks. At the time of calculate, TransactionWitnessSet is null which causes an exception.

Question: Is this implementation ok and we should expect at least an initialized TransactionWitnessSet. Or should we initialize it in this method?

[lilpaul]

imo the lowest impact way to accommodate this situation would be, if numberOfVKeyWitnessesToMock > 0 and witness set is not there, new it up, add the mocks, do the calc, and then remove it if it wasnt there initially, leave it in but remove the mocks if it was.
presumably there is good reason for the witness set not to be newed up during the transaction ctor, and its up to the dev to manage that, but for this function, we are just looking for a way to calculate and set the fee based on what will be the witness count, i dont think it should be erroring if the witness set hasnt been newed yet