.swift

class Blockchain {
    
    private (set) var blocks :[Block] = [Block]()
    private (set) var contracts :[SmartContract] = [SmartContract]()
    
    init() {
        
        // initialize contracts
        initializeContracts()
    }
    
    private func initializeContracts() {
        self.contracts = [InternationalDomesticTransferFeesContract(),MaximumAmountTransferFundsContract()]
    }
  
    // there is more code to the blockchain which you can download from the link in the post 
}