input: Write a python function to check if a list has all unique elements.
  assert is_unique_list([1, 2, 3, 4, 5]) == True
  assert is_unique_list([1, 2, 2, 3, 4]) == False
  assert is_unique_list([7, 8, 9]) == True
  assert is_unique_list([10, 10, 10]) == False
output: def is_unique_list(lst):
      return len(lst) == len(set(lst))