input: Write a function to find the union of two lists. The union of two lists is a list that contains all the unique elements from both lists.
  
  def unionList(list1, list2):
      return list(set(list1 + list2))
  
  list1 = [1, 2, 3, 4, 5]
  list2 = [3, 4, 5, 6, 7]
  assert unionList(list1, list2) == [1, 2, 3, 4, 5, 6, 7]
  
  list1 = [1, 2, 3]
  list2 = [4, 5, 6]
  assert unionList(list1, list2) == [1, 2, 3, 4, 5, 6]
  
  list1 = []
  list2 = [3, 4, 5]
  assert unionList(list1, list2) == [3, 4, 5]
  
  list1 = [1, 1, 2, 2, 3]
  list2 = [2, 3, 4, 4, 5]
  assert unionList(list1, list2) == [1, 2, 3, 4, 5]
  
  list1 = []
  list2 = []
  assert unionList(list1, list2) == []
output: def unionList(list1, list2):
      return list(set(list1 + list2))