input: Write a function to determine if a list contains the largest three numbers and return them in ascending order.
  assert largest_three_numbers([1, 6, 3, 8, 7, 4])==[6, 7, 8]
  assert largest_three_numbers([4, 8, 3, 6, 7, 1])==[6, 7, 8]
  assert largest_three_numbers([9, 2, 5, 7, 6, 1])==[6, 7, 9]
  assert largest_three_numbers([10, 3, 5, 8, 7, 4])==[7, 8, 10]
  assert largest_three_numbers([1, 2, 3])==[1, 2, 3]
output: def largest_three_numbers(lst):
      return sorted(sorted(lst, reverse=True)[:3])