input: Write a python function to print the largest three numbers from a list in descending order.
  assert print_largest_three_numbers([5, 1, 10, 25, 74, 17, 2]) == "74, 25, 17"
  assert print_largest_three_numbers([4, 15, 6, 23, 9]) == "23, 15, 9"
  assert print_largest_three_numbers([99, 23, 45, 12, 89, 77]) == "99, 89, 77"
output: def print_largest_three_numbers(numbers):
      largest_three = sorted(numbers, reverse=True)[:3]
      return ", ".join(map(str, largest_three))