Alexander Korolyov

**Describe the bug** Chem.CanonSmiles generates alternating smiles strings from the same starting molecule, depending on number of runs. **To Reproduce** ``` s = 'COC(=O)[C@@]12[C@@H]3N([C@H]4[C@@]5([C@@H](N([C@H]1[C@]3(C5c1ccc(OC)cc1)C(=O)OC)C(=O)OCc1ccccc1)[C@]4([C@H]2c1ccc(OC)cc1)C(=O)OC)C(=O)OC)C(=O)OCc1ccccc1' Chem.CanonSmiles(s) == Chem.CanonSmiles(Chem.CanonSmiles(s)) # returns False...