input: Write a function to print numbers from 10 to 1 in descending order.
  assert print_numbers_descending() == "10\n9\n8\n7\n6\n5\n4\n3\n2\n1\n"
output: def print_numbers_descending():
      return "\n".join(str(i) for i in range(10, 0, -1)) + "\n"