Fix the error in Python code #13

# Fix the error in the code below
def add_to_shopping_list(item, current_list=[]):
  """
  Adds an item to the shopping list.

  Args:
    item (str): Item to be added
    current_list (list): (optional), the current list of items; assume empty if not provided

  Returns:
    list: List of items in the shopping list
  """
    current_list.append(item)
    return current_list