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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 refine_cell(self, tilde_obj):
        '''
        NB only used for perovskite_tilting app
        '''
        try: lattice, positions, numbers = spg.refine_cell(tilde_obj['structures'][-1], symprec=self.accuracy, angle_tolerance=self.angle_tolerance)
        except Exception as ex:
            self.error = 'Symmetry finder error: %s' % ex
        else:
            self.refinedcell = Atoms(numbers=numbers, cell=lattice, scaled_positions=positions, pbc=tilde_obj['structures'][-1].get_pbc())
            self.refinedcell.periodicity = sum(self.refinedcell.get_pbc())
            self.refinedcell.dims = abs(det(tilde_obj['structures'][-1].cell))