refactor: clean up unit test.

Author: C-nit

tests/test_mixed_reaction_filter.py

@@ -202,16 +202,14 @@ def test_invalid_smiles(filter: MixedReactionFilter) -> None:
 def test_invalid_smiles_from_unexpected_error(filter: MixedReactionFilter) -> None:
     # This does NOT raise InvalidReactionSmiles,
     # but on tokenization TokenizationError / SmilesJoinedTokensMismatch
-    bad_reaction = ReactionEquation.from_string(
+    reaction_with_invalid_smiles = ReactionEquation.from_string(
         "CCC.C[Ni]1<-Cl[Ni](C)<-Cl1>>C[Ni]1Cl[Ni](C)Cl1"
     )
 
-    assert not filter.is_valid(bad_reaction)
+    assert not filter.is_valid(reaction_with_invalid_smiles)
 
-    valid, reasons = filter.validate_reasons(bad_reaction)
+    valid, reasons = filter.validate_reasons(reaction_with_invalid_smiles)
     assert not valid
-    # breakpoint()
-    print(reasons)
     assert reasons[0].startswith(filter.unexpected_error_prefix)