import 'package:stackwallet/wallets/models/tx_data.dart'; import 'package:stackwallet/wallets/wallet/intermediate/bip39_hd_wallet.dart'; import 'package:stackwallet/wallets/wallet/mixins/electrumx.dart'; mixin SparkInterface on Bip39HDWallet, ElectrumX { Future prepareSendSpark({ required TxData txData, }) async { throw UnimplementedError(); } }