def update(self, results):
    'Update set with the union of itself and an iterable with\n        results.'
    self.results.extend((r for r in results if (r not in self.results)))
Update set with the union of itself and an iterable with
results.
def update(self, results):
    'Update set with the union of itself and an iterable with\n        results.'
    self.results.extend((r for r in results if (r not in self.results)))