/// <summary>
 /// loops through all clients and tries to withdraw money from the ATM
 /// </summary>
 /// <param name="atm">ATM to withdraw money from</param>
 /// <param name="clients">ClientContainer from which client data will be taken</param>
 static void PerformWithdrawOperations(ATM atm, ClientContainer clients)
 {
     for (int i = 0; i < clients.Count; i++)
     {
         atm.WithdrawMoney(clients.GetClient(i));
     }
 }
 /// <summary>
 /// loops through all Client objects in a ClientContainer and writes formatted client strings to
 /// a StreamWriter
 /// </summary>
 /// <param name="writer">StreamWriter to write to</param>
 /// <param name="clients">ClientContainer containing cliets to print</param>
 static void PrintClients(StreamWriter writer, ClientContainer clients)
 {
     for (int i = 0; i < clients.Count; i++)
     {
         writer.WriteLine("{0}", clients.GetClient(i).ToString());
     }
 }
        /// <summary>
        /// prints execution results to a given file
        /// </summary>
        /// <param name="fileName">file name to write data</param>
        /// <param name="atm">ATM object on which money withdrawing was performed</param>
        /// <param name="clients">ClientContainer object containing client data</param>
        static void PrintResults(string fileName, ATM atm, ClientContainer clients)
        {
            using (StreamWriter writer = new StreamWriter(fileName)) {
                for (int i = 0; i < clients.Count; i++)
                {
                    writer.WriteLine("{0}", clients.GetClient(i).WithdrawOperationString);
                }

                writer.WriteLine();
                writer.WriteLine("{0}", atm.ToString());
            }
        }