[Ref / Label] make equality safe for unrelated types

masque/test/test_ref.py

@@ -87,3 +87,9 @@ def test_ref_scale_by_rejects_nonpositive_scale() -> None:
 
     with pytest.raises(MasqueError, match='Scale must be positive'):
         ref.scale_by(-1)
+
+
+def test_ref_eq_unrelated_objects_is_false() -> None:
+    ref = Ref()
+    assert not (ref == None)
+    assert not (ref == object())