input: Write a function to remove duplicates from a list and return the list with unique elements in the same order they appear.
  
  def remove_duplicates(my_list):
   return list(dict.fromkeys(my_list))
  
  assert remove_duplicates([1, 2, 3, 4, 3, 2, 1]) == [1, 2, 3, 4]
  assert remove_duplicates(["a", "b", "a", "c", "b"]) == ["a", "b", "c"]
  assert remove_duplicates([]) == []
  assert remove_duplicates([1, 1, 1, 1]) == [1]
  assert remove_duplicates([5, 6, 7, 8, 8, 7]) == [5, 6, 7, 8]
output: def remove_duplicates(my_list):
      seen = set()
      result = []
      for item in my_list:
          if item not in seen:
              seen.add(item)
              result.append(item)
      return result