public async Task <TransactionResult> GetTransactionAsync(uint256 txId, CancellationToken cancellation = default(CancellationToken)) { if (txId == null) { throw new ArgumentNullException(nameof(txId)); } var tx = _Cache.GetTransaction(txId); if (tx != null) { return(tx); } tx = await _Client.GetTransactionAsync(txId, cancellation); _Cache.AddToCache(tx); return(tx); }