input: Write a function to simulate a bank account deposit and withdrawal operations.
  assert BankAccount(123, 1000).deposit(500) == 1500
  assert BankAccount(123, 1000).withdraw(300) == True
  assert BankAccount(123, 1000).withdraw(1300) == False
output: class BankAccount:
      def __init__(self, account_number, balance):
          self.account_number = account_number
          self.balance = balance
      
      def deposit(self, amount):
          self.balance += amount
          return self.balance
      
      def withdraw(self, amount):
          if amount <= self.balance:
              self.balance -= amount
              return True
          else:
              return False