input: Write a function to find the common elements between two given lists. The function should return a list containing all elements that are present in both input lists. If there are no common elements, the function should return an empty list.
  assert find_common_elements([1, 2, 3], [2, 3, 4])==[2, 3]
  assert find_common_elements([1, 2, 3], [4, 5, 6])==[]
  assert find_common_elements([], [4, 5, 6])==[]
  assert find_common_elements([1, 2, 3], [])==[]
  assert find_common_elements([1, 1, 2], [2, 1, 1])==[1, 2]
output: def find_common_elements(list1, list2):
      return list(set(list1) & set(list2))