sign method
Implementation
TxBuilder sign(Account account) {
if (_txParam.value.isEmpty ||
_txParam.gasPrice.isEmpty ||
_txParam.gasLimit.isNegative ||
_txParam.to.isEmpty) {
throw Exception(ErrorCode.invalidTxParam);
}
// chainId validation: chainId of wallet must match the one in txParam
if (account.wallet.networkParam.chainId != _txParam.chainId) {
throw Exception(ErrorCode.invalidWallet);
}
_signedTx = account.signTransaction(_txParam);
return this;
}