let wallet = Wallet(privateKey: nil)
// Load a wallet from the private key.
let privateKey = PrivateKey(hex: data)
let wallet = Wallet(privateKey: privateKey)
let wallet = Wallet(privateKey: nil)
try wallet.generateKeystore(password: "YOUR_WALLET_PASSWORD")
try wallet.save(filepath: "YOUR_STORAGE_PATH")
// Load a wallet from the keystore.
let jsonData: Data = try Data(contentsOf: "YOUR_KEYSTORE_PATH")
let decoder = JSONDecoder()
let keystore = try decoder.decoder(Keystore.self, from: jsonData)
let wallet = Wallet(keystore: keystore, password: "YOUR_WALLET_PASSWORD")