The code that will be used in this chapter can be found on GitHub at https://github.com/PacktPublishing/Mastering-Blockchain-Programming-with-Solidity/tree/master/Chapter10.
You'll find a submodule folder called MultiSigWallet in the Chapter10 folder. If the MultiSigWallet folder is empty, run the following command under the Chapter10 folder to update it:
git submodule update --init --force --recursive --remote
In this chapter, we will be using the Gnosis multisig DApp GitHub repository as a submodule, which is present in the MultiSigWallet folder. The Gnosis repository uses the multisig Solidity contract that was written by ConsenSys. The project is old and hasn't been upgraded to use the latest version of Solidity. Therefore, the following Solidity version and tools are required for this project...