input: Write a function to calculate the total cost of a shopping cart. The function should take a list of items, each represented by a dictionary with keys "name", "price", and "quantity", a shipping cost, and a tax rate. It should return the total cost, including the sum of item prices, the shipping cost, and the tax applied to the sum of item prices.
  assert calc_total_cost([{"name": "widget", "price": 10, "quantity": 5}, {"name": "thingy", "price": 7, "quantity": 3}, {"name": "doodad", "price": 5, "quantity": 2}], 7.50, 9.5)==79.3375
  assert calc_total_cost([{"name": "apple", "price": 1, "quantity": 10}, {"name": "banana", "price": 0.5, "quantity": 20}], 5.00, 8.0)==31.04
  assert calc_total_cost([], 0, 0)==0.0
output: def calc_total_cost(items, shipping_cost, tax_rate):
      total_item_cost = sum(item["price"] * item["quantity"] for item in items)
      tax = total_item_cost * (tax_rate / 100)
      total_cost = total_item_cost + tax + shipping_cost
      return total_cost