Update self to include only the symmetric difference with other.

def symmetric_difference_update(self, other):
		"""Update self to include only the symmetric difference with other."""
		other = setlist(other)
		indices_to_delete = set()
		for i, item in enumerate(self):
			if item in other:
				indices_to_delete.add(i)
		for item in other:
			self.add(item)
		self._delete_values_by_index(indices_to_delete)