code: def _rebuffer(self):
          
          results = []
          exceptions = []
          for i in xrange(self.stride):
              try:
                  results.append(self.iterable.next())
                  exceptions.append(False)
              except Exception, excp:
                  results.append(excp)
                  exceptions.append(True)
          self._repeat_buffer = repeat((results, exceptions), self.n)
docs: (very internal) refill the repeat buffer