input: Write a python function to convert a list to a set using a list comprehension and check if it matches the set conversion.
  assert list_to_set([1, 2, 3, 4, 5]) == set([1, 2, 3, 4, 5])
  assert list_to_set([5, 5, 6, 6, 7, 7, 8, 8]) == set([5, 6, 7, 8])
  assert list_to_set([]) == set()
output: def list_to_set(lst):
      return set([item for item in lst])