input: Write a python function to find common elements in two lists.
  assert find_common_elements([1, 2, 3, 4], [2, 3, 4, 5]) == [2, 3, 4]
  assert find_common_elements([10, 20, 30, 40], [15, 20, 25, 30]) == [20, 30]
  assert find_common_elements([7, 8, 9], [10, 11, 12]) == []
  assert find_common_elements([], [1, 2, 3]) == []
  assert find_common_elements([1, 1, 1], [1, 1, 1]) == [1, 1, 1]
output: def find_common_elements(list1, list2):
      return [element for element in list1 if element in list2]