input: Write a function to calculate the total cost of a shopping cart. The function should consider the item prices, quantity, shipping cost, and any applicable taxes. The function should return the total cost as a float.
  
  assert calculate_total_cost([{"name": "widget", "price": 10, "quantity": 5 }, {"name": "thingy", "price": 7, "quantity": 3 }, {"name": "doodad", "price": 5, "quantity": 2 }], 7.50, 0.095)==112.554
  assert calculate_total_cost([{"name": "item1", "price": 5, "quantity": 2}, {"name": "item2", "price": 3, "quantity": 3}], 4.50, 0.08)==27.54
  assert calculate_total_cost([], 0, 0)==0
  assert calculate_total_cost([{"name": "product", "price": 100, "quantity": 1}], 10, 0.10)==121.0
output: def calculate_total_cost(items, shipping_cost, tax_rate):
      subtotal = sum(item["price"] * item["quantity"] for item in items)
      total_cost = subtotal + shipping_cost
      total_cost += total_cost * tax_rate
      return round(total_cost, 2)