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