input: def removeDuplicates(array: List[int]) -> List[int]:
      """Return a list containing unique elements from given array, in same order.
      >>> removeDuplicates([1, 2, 3, 1, 2])
      [1, 2, 3]
      >>> removeDuplicates([4, 4, 4, 4])
      [4]
      """
      return list(dict.fromkeys(array))
output:     seen = set()
      result = []
      for num in array:
          if num not in seen:
              seen.add(num)
              result.append(num)
      return result