input: def find_max_in_list(nums: list):
      """Retrieve the largest number from the list.
      >>> find_max_in_list([1, 2, 3])
      3
      >>> find_max_in_list([5, 3, -5, 2, -3, 3, 9, 0, 123, 1, -10])
      123
      """
output:     if not nums:
          return None
      return max(nums)