input: Write a function to find the largest three numbers in a given list. Return a list containing these three largest numbers in descending order.
  
  assert find_largest_three([1, 6, 3, 8, 7, 4])==[8, 7, 6]
  assert find_largest_three([9, 1, 2])==[9, 2, 1]
  assert find_largest_three([5])==[5]
output: def find_largest_three(nums):
      return sorted(nums, reverse=True)[:3]