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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def integrate(self):
 """ Integrate without adding an integration constant. """

    if -1 in self._data:
      raise ValueError("Unable to integrate term that powers to -1")
    return Poly(OrderedDict((k + 1, v / (k + 1))
                            for k, v in iteritems(self._data)),
                zero=self.zero)