input: Write a python function to find common elements in two lists.
  assert common_in_two_lists([1, 2, 3, 4, 5], [4, 5, 6, 7, 8]) == [4, 5]
  assert common_in_two_lists([10, 20, 30], [30, 40, 50]) == [30]
  assert common_in_two_lists(['a', 'b', 'c'], ['b', 'c', 'd']) == ['b', 'c']
output: def common_in_two_lists(list1, list2):
      return list(set(list1) & set(list2))