code: def addSuccess(self, test, capt=None):
          
          time_taken = self._register_time(test, 'success')
          if self.timer_fail is not None and time_taken * 1000.0 > self.threshold:
              test.fail('Test was too slow (took {0:0.4f}s, threshold was '
                        '{1:0.4f}s)'.format(time_taken, self.threshold / 1000.0))
docs: Called when a test passes.