private void FetchConfirmedTransactions(PaymentAddress address, UInt64 limit, UInt64 fromHeight, Action <ErrorCode, HashList> handler) { GCHandle handlerHandle = GCHandle.Alloc(handler); IntPtr handlerPtr = (IntPtr)handlerHandle; ChainNative.chain_fetch_confirmed_transactions(nativeInstance_, handlerPtr, address.NativeInstance, limit, fromHeight, internalFetchTxnsHandler_); }