input: Write a python function to calculate the total cost of a list of products.
  assert calculateTotalCost([Product("Apple", 1.99, 2), Product("Banana", 0.79, 5)]) == 11.75
  assert calculateTotalCost([Product("Milk", 2.50, 1), Product("Bread", 1.50, 2)]) == 5.50
  assert calculateTotalCost([]) == 0
output: class Product:
      def __init__(self, name, price, quantity):
          self.name = name
          self.price = price
          self.quantity = quantity
  
  def calculateTotalCost(products):
      total_cost = 0
      for product in products:
          total_cost += product.price * product.quantity
      return total_cost