input: Write a function to simulate a simple ATM machine. Design an Account class with methods to initialize an account, deposit, and withdrawal. The ATM class should be able to create accounts, perform deposits, withdrawals, and print account balances for a given user name. If the function is given an empty input, it should return True. 
  assert ATM().printBalance("Alice") == None
  assert ATM().withdrawal("Alice", 100) == None
  assert ATM().deposit("Alice", 200) == None
  ATM().createAccount("Alice", 500)
  assert ATM().printBalance("Alice") == None
  assert ATM().withdrawal("Alice", 100) == None
  ATM().deposit("Alice", 200)
  assert ATM().printBalance("Alice") == None
output: class Account:
      def __init__(self, name, balance):
          self.name = name
          self.balance = balance
  
      def deposit(self, amount):
          self.balance += amount
  
      def withdrawal(self, amount):
          if amount <= self.balance:
              self.balance -= amount
  
  class ATM:
      def __init__(self):
          self.accounts = {}
  
      def createAccount(self, name, balance):
          if name:
              self.accounts[name] = Account(name, balance)
  
      def deposit(self, name, amount):
          if name and name in self.accounts:
              self.accounts[name].deposit(amount)
  
      def withdrawal(self, name, amount):
          if name and name in self.accounts:
              self.accounts[name].withdrawal(amount)
  
      def printBalance(self, name):
          if name and name in self.accounts:
              print(self.accounts[name].balance)