input: def delete_item_from_list_via_rest_api(item: str) -> str:
      """ Deletes an item from a list via a REST API in Python using Flask.
      This function simulates the deletion of an item from a list that is served by a REST API.
      The list contains several items which can be displayed via a GET request route.
      An item can be deleted via a DELETE request route.
      If the item is found and deleted, the function should return "Item successfully deleted."
      If the item is not found, the function should return "Item not found."
      >>> delete_item_from_list_via_rest_api("Banana")
      'Item successfully deleted.'
      >>> delete_item_from_list_via_rest_api("Grape")
      'Item not found.'
      """
output:     items = ["Apple", "Banana", "Cherry"]
      if item in items:
          items.remove(item)
          return "Item successfully deleted."
      else:
          return "Item not found."