fileprivate func startNode() throws {
    var error: NSError?
    let bootNodes = GethNewEnodesEmpty()
    bootNodes?.append(GethNewEnode(Constants.Ethereum.enodeRawUrl, &error))

    let genesisPath = Bundle.main.path(forResource: "rinkeby", ofType: "json")
    let genesis = try! String(contentsOfFile: genesisPath!, encoding: String.Encoding.utf8)

    let config = GethNewNodeConfig()
    config?.setBootstrapNodes(bootNodes)
    config?.setEthereumGenesis(genesis)
    config?.setEthereumNetworkID(4)

    let datadir = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
    ethereumNode = GethNewNode(datadir, config, &error)

    try ethereumNode.start()

    if let error = error {
        throw EthereumError.nodeStartFailed(error: error)
    }
}

fileprivate func startSync() throws {
    if let syncProgress = try? self.ethereumNode.getEthereumClient().syncProgress(self.ethereumContext) {
        self.isSyncMode = true
    } else if self.isSyncMode {
        self.isSyncMode = false
    }
}