@@
expression X;
identifier Y;
@@
(
  Py_DECREF(Y); Y = NULL;
|
  Py_XDECREF(Y); Y = NULL;
|
- Py_DECREF(X); X = NULL;
+ Py_CLEAR(X);
|
- Py_XDECREF(X); X = NULL;
+ Py_CLEAR(X);
)