input: Write a python function to find common elements in two lists.
  assert find_common_elements([1, 2, 3], [3, 4, 5]) == [3]
  assert find_common_elements([10, 20, 30, 40], [30, 40, 50, 60]) == [30, 40]
  assert find_common_elements(['a', 'b', 'c'], ['c', 'd', 'e']) == ['c']
output: def find_common_elements(list1, list2):
      return list(set(list1) & set(list2))