input: from typing import List
  
  def remove_duplicates(my_list: List) -> List:
      """Remove duplicates from the given list and return a list of unique elements.
      >>> remove_duplicates([1, 2, 3, 4, 3, 2, 1])
      [1, 2, 3, 4]
      """
      return list(dict.fromkeys(my_list))
output:     return list(dict.fromkeys(my_list))