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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 get_oxi_state_decorated_structure(self, structure):
 """ Get an oxidation state decorated structure. This currently works only for ordered structures only. Args: structure: Structure to analyze Returns: A modified structure that is oxidation state decorated. Raises: ValueError if the valences cannot be determined. """

        s = structure.copy()
        if s.is_ordered:
            valences = self.get_valences(s)
            s.add_oxidation_state_by_site(valences)
        else:
            valences = self.get_valences(s)
            s = add_oxidation_state_by_site_fraction(s, valences)
        return s