input: Write a function to remove duplicates from a given list and return the list with unique elements in the original order.
  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([1, 1, 1, 1])==[1]
  assert remove_duplicates([])==[]
  assert remove_duplicates([5, 6, 7, 5, 7, 8])==[5, 6, 7, 8]
  assert remove_duplicates(['a', 'b', 'a', 'c', 'b'])==['a', 'b', 'c']
output: def remove_duplicates(my_list):
      return list(dict.fromkeys(my_list))