input: Write a python function to calculate the item cost given its size and weight using the CostCalculator class.
  assert CostCalculator(10, 20).calculate_item_cost() == 20.0
  assert CostCalculator(5, 15).calculate_item_cost() == 7.5
  assert CostCalculator(8, 10).calculate_item_cost() == 8.0
output: class CostCalculator:
      def __init__(self, size, weight):
          self.size = size
          self.weight = weight
          
      def calculate_item_cost(self):
          return self.size * self.weight / 10