309 static PyObject *
310 urj_pyc_set_frequency (urj_pychain_t *self, PyObject *args)
311 {
312     urj_chain_t *urc = self->urchain;
313     uint32_t freq;
314     if (!PyArg_ParseTuple (args, "i", &freq))
when PyArg_ParseTuple() succeeds
taking False path
315         return NULL;
316     if (!urj_pyc_precheck (urc, UPRC_CBL))
when considering value == (int)0 from chain.c:316
taking True path
317         return NULL;
318 
319     urj_tap_cable_set_frequency (urc->cable, freq);
320     return Py_BuildValue ("");
321 }
returning (PyObject*)NULL without setting an exception