input: 
  def create_store_item(item_id: int, name: str, price: float, description: str) -> StoreItem:
      """ Create an instance of StoreItem with given details.
      >>> create_store_item(1, 'Book', 15.99, 'A great book')
      'Book, $15.99'
      >>> create_store_item(2, 'Pen', 2.99, 'A blue pen')
      'Pen, $2.99'
      """
      return StoreItem(item_id, name, price, description)
  
output:     return f"{name}, ${price:.2f}"