input: from typing import List
  
  def unionList(list1: List[int], list2: List[int]) -> List[int]:
      """
      Combine two lists and return a list of unique elements from both lists.
      
      >>> unionList([1, 2, 3, 4, 5], [3, 4, 5, 6, 7])
      {1, 2, 3, 4, 5, 6, 7}
      """
      return set(list1 + list2)
output:     return list(set(list1 + list2))