code: def symmetric_difference_update(self, other):
          
          items_to_add = [item for item in other if item not in self]
          items_to_remove = set(other)
          self._update_items(
              [item for item in self.items if item not in items_to_remove] + items_to_add
          )
docs: Update this OrderedSet to remove items from another set, then
          add items from the other set that were not present in this set.
  
          Example:
              >>> this = OrderedSet([1, 4, 3, 5, 7])
              >>> other = OrderedSet([9, 7, 1, 3, 2])
              >>> this.symmetric_difference_update(other)
              >>> print(this)
              OrderedSet([4, 5, 9, 2])