sign method
Implementation
@override
KasTxData sign() {
for (int i = 0; i < txData.inputs.length; i++) {
txData.messages.add(txData.inputs[i].signatureScript);
final signautre = wallet.sign(txData.inputs[i].signatureScript);
txData.inputs[i].signatureScript = addFixs(signautre);
}
txData.isSigned = true;
return txData;
}