code: def add_oxidation_state_by_guess(self, **kwargs):
          
          oxid_guess = self.composition.oxi_state_guesses(**kwargs)
          oxid_guess = oxid_guess or \
                       [dict([(e.symbol, 0) for e in self.composition])]
          self.add_oxidation_state_by_element(oxid_guess[0])
docs: Decorates the structure with oxidation state, guessing
          using Composition.oxi_state_guesses()
  
          Args:
              **kwargs: parameters to pass into oxi_state_guesses()