input: def remove_duplicates(array: List[int]) -> List[int]:
      """ Remove duplicates from a given array and return the array with unique elements.
      >>> remove_duplicates([1, 2, 2, 3, 4, 4, 5])
      [1, 2, 3, 4, 5]
      >>> remove_duplicates([5, 5, 5, 5, 5])
      [5]
      """
output:     seen = set()
      result = []
      for num in array:
          if num not in seen:
              seen.add(num)
              result.append(num)
      return result